Paul Harrell did a comparison shooting review of the RIA & the Colt in 45acp that's worth watching if your considering the RIA.
I've had the basic stock model RIA for a couple of years that's shot well over 1,000 rounds, probably closer to 1500, from reloads to defense stuff with different magazines. I can't recall a failure to feed or eject and it always locks open after the last shot. IMO the trigger's pretty good and other people that have shot it agree. The GI sights are nothing great but they've worked well enough for me for the kind of shooting I do so far. I'd like to have a Colt but can't fault my RIA.
Whatever you decide on the big problem now will be finding what you want at a halfway decent price.
