I have a Porter Cable framing nailer, the clipped head variety and it has performed great for my limited use. I cannot quote the angle but the clipped head allows for a higher angle from horizontal, which gives more clearance. Thats the gist of it. But I have had very good results with all the Porter Cable nailers.

You'll find a lot of expertize over on the Fine homebuilding Magazine site, the Breaktime forum.
I have a Porter Cable framer, too, but it's the Roundhead version, FP 350. The roundhead nails are required in areas with hurricane exposure. Not that we get many of those here in Arizona, but you can't be too careful.
I haven't used the nailer much yet, except for practicing on scrap, but it seems to work fine. You'll need ear protection! It's loud. It works even better on skin than on wood, so be careful!
Sorry I couldn't provide a link to the Breaktime site.

I'm no pro, but have put some time in with framing nailers, both around the house and with Habitat. I've been pleased with the Paslode discharge nailer using D-head nails, and I wouldn't consider buying anything else. It is VERY nice to not have an air hose to drag around, up a ladder, across the yard, whatever. Very much worth the money.

They have an air-powered version, too, if you'd prefer to stick with air.

I just bought a Porter Cable FR350 round head framing nailer. I used it to build my shed and it worked awesome. The adjustable depth control is nice as is the adjustable exhaust and single or rapid fire modes. It is a great nailer for the price. HD has it for $299 in my neck of the woods. I don't think the clipped head nailers come in the 20-22 degree style only the round head ones do. The only thing the angle does is allow you to get into tighter areas. You probably noticed that with the finish nailer as the angled one allows you to get into tighter areas say for crown molding. I think the clipped heads use the 28 or higher degree nails. Either way, I love mine. Not one jam. Check you local code to see if you can use clipped head nails. I noticed the local home centers had more of a selection for clipped head nails. Otherwise you may get stuck buying larger box of nails then you really need.

I'd avoid clipped head nailers. Lots of building codes no longer allow them so nails are going to get harder to find.

Go with full head strip nailers.

Mine is a Milwauke. It's lightweight and has a depth control. It also has a smooth rubber boot for the head that can be removed to expose s sharp grip for doing toenail drives.

Amazon has some great deals from time to time.

Let's talk nails first - 20-22 degree round-head plastic collation and 30-34 degree clipped/roundrive paper collation. There's 28 degree wire collation used by Bostich as well.

I recommend a Paslode F350S or the Hitachi NR90AD for clipped-head nails or Roundrive nails. I recommend the Hitachi NR90AE or NR83A2S for round-head nails.
Milwaukee has just brought out a line of framing nailers recently but I already own 2 and don't need a third.

I use either the Hitachi nails or Paslode nails in my nailers.

There are at least 2 cordless framers: Paslode (clipped-head 3-1/4" or less) and Hitachi (NR90GC and NR90GR) 3-1/2" or less. The fine print for all the cordless models does NOT recommend their use with 3" to 3-1/2" ring-shank nails in pressure-treated lumber. I have some deck-building applications where I typically use 3" ring-shank nails in PT plywood and lumber, so I have only the non-cordless nailers.

Consider getting a factory-reconditioned nailer and save money on the deal: http://portercable.cpoworkshop.com/nailers_and_staplers/framing_nailers/

I have a Porter Cable FR350 and it works fine. I've also used most of the other brands and they all work fine too. They all fire nails into whatever your aiming at.

I've read of people buying the cheap-o (less than $100) nailers from Harbor Freight and having great results too.

If you aren't going to use it very often, I'd get the Harbor Freight one. You could buy 3 (or more) of them and still pay less than one Porter Cable or other similar brands.

If you were going to build several houses with it, I'd probably spend a bit more for a better model.

Cheap-o nailers. Yes, they will drive nails and get the job done. I have never read where someone thought that they did not get their money's worth of use from one of these tools. They are sufficiently reliable for most folks' needs.

Unless the nailer is designed to NOT require lubrication (some Senco units fall in this category), proper attention to oiling the nailer will extend its useful life considerably.

I do recommend that quality nails be used, regardless of what nailer drives them. I have read where someone used cheap-o nails that damaged the nailer.

Here's one consideration for cheap-o nailers: IF they quit working, you may not be able to get repair parts for them. If you can cobble together a repair solution, great. Otherwise, you will have to discard the tool.

Paper-collated nails: At the end of each work period, remove ALL of the nail strips from the tool. Otherwise feeding problems may occur at the next use. I don't do this for the plastic-collated nails.

All mine are re-man porter cables. I agree with the quality of nails/brads. Check out re-manufactured porter cables. We had a porter cable store here for a short while.
I loaded up on a 16 guage finish and 90 wire stapler and about 40 lbs of bullets for around 200 dollars. The porter cable framer is a strong unit. For cost and production they are hard to beat.

PC framers are good equipment, new or remanufactured. There is one consideration for PC framers that may apply to other brands: The round head version (FR350) and the clipped head version (FC350) are indistinguishable except for the small R or C on the label. CANNOT tell side by side.
On a Habitat site, FC350's were in use. A volunteer brought their own FR350 along with round head nails for it. You guessed it, another volunteer reloaded the FC350 with round head nails. Jammed it up good. The site leader was very unhappy about having to unjam the FC350; developed quite an attitude for any volunteer showing up with their own framing gun (that would be me).

If more than one type of nail is available on site, there is a good chance that someone who has never used a framing nailer will feed it incorrectly. A nail is a nail, right?

While you wait for that PC FC350 to arrive, let's talk air.
Framing guns like more pressure than the finish and brad nailers use. The limit on most is 120 psi, but I set the regulator at 100 psi for the nailers that I have. Be sure to set it back down to the lower pressures for the finish nailer OR install a second regulator on the air hose plugged into the finish or brad nailer.

Another matter is triggers. I recommend a restrictive-fire mode for a framing nailer. Some nailers have a trigger setting while others replace the trigger with a special unit that only allows one nail driven per pull of the trigger.
The other mode is a bounce-fire mode. Hold the trigger down and each time the nose of the nailer hits wood, another nail is set. It takes some practice to do it well.
Here's why restrictive fire:
1. It's safer since the trigger must be released before the next nail drives.
2. It's easier to learn if someone else needs to use your nailer.
3. It avoids double-firing when the recoil of the first nail causes the nose safety to bounce and shoot a second nail, typically not fully driven. That second nail is probably NOT where you wanted one to go.
4. Single-shot mode won't slow you down, but it will allow you to place the next nail where you want it rather than wherever the nailer bounces to.

After you are all set up, get a scrap 4x4 and fire 2-3 magazines of nails into it. Eye and hearing protection, of course.

I agree good nails and a properly oiled gun will provide excellent service. I love my FR350 gun and $199 is a good price. I was shocked to learn it was made in Taiwan per PC specifications. I guess nothing is made in the USA anymore.

Just following up -- I bought a 28 degree nailer from harbor freight. It was advertised for $79 and I had a coupon for some more off.

I didn't expect much from it but so far it has been great. I've shot a few hundred 3"x.120 and 3.5"x.131 nails thru it with no jams. It seems to sink nails into both old wood and PT wood w/o problems. The only real gripe I have with it is that the depth of drive is a PITA to adjust, so I've adjusted it to drive nails flush when face nailing and I've been finsihing toe-nails by hand. I need the exercise swinging the hammer anyway :)

I've used Grip-Rite and HF nails. The HF nails were kind of a disappointment as the box said "galvanized" but all they have is a thin yellow zinc coating. I was expecting hot dip but for $27 for 2000 nails I guess I can't complain. I'm using the nails indoors so its probably a non-issue.

I'm sure this thing wouldn't last long on a real jobsite but with the usage I will give it looks like I will get my money's worth out of it.

Thanks to all that replied.