I'd ask them both for customer referrals so you can ask the customer what happened.

Hi sheckylovejoy. I have the same dilemma. Did you ever get an explanation for which is better? And what did you use? How did your patio and walkways turn out?

Thanks for your help.

My two cents: I've used polymeric and regular sand for various paver installations at my place, and the polymeric has proven to hold together better for longer, resist weed growth between pavers, and need maintenance (refilling cracks and eroded sections) about half as often as regular sand.

It's not a perfect solution by any means, but if you're going to bother jointing your pavers, it's worth the extra cost in my experience.

A few posts on the projects I've used it for, and my installation notes as well:

http://havingfunalongtheway.com/building-a-mow-strip-for-your-lawn-part-1/

In my limited experience, the polymeric sand holds the overall structure of the paver together better. The problem is the sand tends to chip away at the surface. In a non-polymeric installation, the remaining sand tends to even out the missing sand and you do not notice it as readily. The reason a contractor would not like this is that he has to keep coming back to re-apply new polymeric sand into the areas that have chipped out. I suppose you could learn to do those repairs yourself.

One thing I have wondered about - but never tried - is whether you could use polymeric sand on the base of the pavers and part way up the sides. Wet that and let it harden. Could you then finish the top with regular sand? That would give you more structural integrity below and up the side of the pavers, but the finish on top would be smooth and much easier to self-repair with more paver sand.

I do not have enough experience to even know if the polymeric sand is allowed to be used as the one-inch sand layer under the pavers. Is polymeric sand specified only for the joints between pavers, or can it be used as a base as well?