I really don't have a basis for comparison, since I'm building two rifles based LR-308 compatible lowers and I haven't done anything with an AR-10 at all.
The research I did and the people I trust who have been down both roads made me come away thinking that there are more options for the LR-308 - there are more outfits making components, there are more magazine options, the prices are a bit lower on the parts, etc. Since I'm capable of turning my own barrels and doing all the machining, getting into comparisons of the finished rifles doesn't sway me as much as component availability, magazine compatibility with my intended chambering, etc.
There are people who complain about DPMS quality, or that they don't like that DPMS uses 6061 aluminum on their receivers while the AR-10 is made from 7075. OK, so if someone really has their panties in a wad about this point, they can get a LR-308 pattern lower made by an outfit like Tactical Machining that is 7075. The truth is, most people can't tell you the difference between 6061 and 7075 any more than they can tell you the difference between forged vs. cast vs. "billet" as the starting point for a receiver. Far too many people spout these specs without understanding the requirements or material science/engineering.
Sorry I can't be of more assistance in this matter, that's just the way this market segment is just now...