I'm not familiar with the DR and my Mac is a 6.5HP model. I would say they are both well built, so it comes down to preferences. When I bought mine, the chute seemed adequate and the 3" chipper feed seemed good. I now wish I had spent the extra few hundred and gotten the larger model. The hopper would have been larger and less prone to feeding clogs. But for how much I use it, I can be satisfied with the smaller one.

I have a mackissic 12pt10 and it is a great machine. I believe it is the next model down from the one your looking at. Its well built and I've had zero problems with it in the 4 years I've owned it. I checked DR website and the dr model you looked at can only chip 3.5 inch branches which is what my 12pt10 can chip. The SC1650E chips 4 inch branches, so if it were me I'd go with the Mac. Seems you get a little more engine and a little more capacity for the money.

I purchased the DR 12hpchipper/shredder and the same day I ordered the machine they discontinued the chipper/shredders with the exception of one smaller hp unit. I also contacted DR inquiring if MacKissic manufactured the machines for them. I was told that MacKissic does manufacture the machines for DR. This was quite obvious by viewing the pictures. The only reason I bought the DR vs the MacKissic was because I paid $3674 for the DR and the cheapest MacKissic I could get was for $3699. I also received a 3 year warranty on the DR vs a 2 year warranty for the MacKissic. Haven't used it yet as I am awaiting a cooler autumn here in SC.