I have a pre-ban Olympic lower I bought as a kit. Colt H bar upper, and it has worked flawlessly for a long time. Olympic also has a lifetime warranty. I own colt, dpms, Olympic and have no complaints for any of them. I've been going dpms a lot due to the low cost of the uppers and lowers for building. I like the pro series flat top uppers for the extra meat around the bolt carrier for stiffness. Cons are no forward assist or dust shield. The hot deal around here ( Dallas Texas ) has been rock river, a collapsible stock 16", A3 with a hard case and 2 mags out the door for 695.00 If you look at ar15dotcom, in the equipment exchange, a vender called ROSECO, is the guy selling these at the local gunshows. He also is a stocking parts dealer for Wilson Combat. The only brands I stay away from always are nessards, and essential arms. I would try a stag, rr, compass lake, sun devil, bushmaster, S&W or Fulton armory, but do not have any personal experience with them, just friends who are happy with them. I recently built a complete upper minus bolt carrier for a friend with all model one sales parts, it works well and he reports shoots well.
Have fun with your new purchase, and post pics.