Has anybody used them? How are they? Problems?  Thanks in advance

need mo info.

100% receivers? NDS-3 receivers are da bomb.  I just noticed there is a recommendation to not use the Tapco G2 single hook trigger with them.  I don't know why, mine works fine with the G2 (after I installed the disconnector spring).  

80% bent receivers? I dunno.

If you are going to build more than 2 or 3. Bending them yourself is the way to go. Its not that hard. You dont have all the FFL hassle. And after number 2 or 3 the jig has paid for itself. Expecially if you buy my receiver jig on equiptmen exchange board

I have not used the Bentmetal but I have used the ColdSteel ones several times and am happy with the quality. The ColdSteels have all the stampings in them. all you need to finish them is a Dremel tool, some files, a drill motor or drill press and drills/reams. Much cheeper than a bending jig and press, But each-to-his-own.
Remember you do have to weld in the lower rails and harden them also.