One area where the Rock Island Armory guns unjustly suffer some unfair criticism, is their frames and slides are cast, rather than forged. I say "unjustly" because I'm not under the impression that has lowered their quality any, if at all. There are several high cost 1911's on the market today that utilize cast frames and slides. All deliver good quality, performance, and longevity.
Modern vacuum investment casting techniques have improved greatly over the last 20 years. To the point there is really little difference in actual measured strength in cast vs. forged. Ruger has proven this more than any manufacturer. Most everything Ruger produces today uses some from of investment casting. The receivers of the Mini 14, Model 77 bolt action, Red Label O/U shotgun, and even the #1 falling block rifle, (considered to be one of the strongest actions available), all use the vacuum investment casting process to create their actions. As do all of the steel framed Super Blackhawks, Redhawks, and GP-100 revolvers.
Springfield Armory uses investment cast actions on all of their M1-A rifles. And several other manufacturers today use investment casting to produce their weapons. Even MIM has come a long way in a very short time. It's methods and quality are very high. You rarely hear of a MIM part failing today. Even high shock parts like 1911 slide stops hold up well that have been manufactured by modern MIM methods.
So while some may still feel that anything but a forged part is inferior. That perception is fading fast, as modern investment casting and MIM methods keep improving. I don't feel RIA guns give up anything in the quality department because of their use of it.