I had the opportunity while in New Hampshire to visit KT Ordnance, and watched as my lowers were milled out of T6 billet. It is really amazing to watch a receiver "appear" out of a block of aluminum! CNC machinery just makes it look so simple. His lowers are so pretty (the milling process makes them look jewelled) you almost hate to finish them, and the edges are so sharp and precise you almost think they'll cut you.
Rick is a Class III manufacturer and does a bunch of other stuff besides these lowers, but he puts a lot into them nonetheless.
In addition to AR-15/AR-10 lowers, he also makes 80% P228 frames, offers a 1911 frame with a slick tactical rail integrated into the dust cover, and is working on a version of the Beretta M9. It's not on his website, but he also can make a semiauto lower for the original AR-10 from the 1950s if you happen to have one of the old Portugueuse/NATO/Sudan parts kits. I got a couple of those lowers while I was there, too.
This is a solid, competent and extremely honest guy who definitely knows what he's doing. I have pictures I took while making my lowers if anyone wants to post them. Since I was there in person, we went ahead and completed my lowers, but his 80% lowers are top notch. Very precisely made - CNC, after all - and all the holes are "spotted" so you'll have a much easier time finishing the lower. He can also program the mill to engrave stuff such as a name or ID number on your lower.
I really can't say enough good things about the guy; I'd recommend his stuff to anybody and you absolutely don't have to worry about your money.
Also, a few times a year he has "picnics" where he opens up the shop to anyone who wants to come up in person and make their own 100% lowers. I believe he posts that info on his website.
Speaking of which: http://www.ktordnance.com/kto/products.php