I've never owned a 5 inch RIA 1911, but I've owned 2 Armscor compacts (3.5 inchers), one RIA one Citidel. I never had a problem wit them. They ate any ammo i put in them. I ran anything from TulAmmo to all different kinds of self defense JHP ammo. If the compacts could eat anything, then the 5 inchers should be awesome.
Right now my primary gun is a Kimber Pro BP Ten II doublestack 1911 (4 inch, holds 14 rounds of .45ACP), I would rather be carrying a 5 inch RIA or Citidel 1911.
http://forums.1911forum.com and http://forum.m1911.org are good resources for research on 1911s.