I have the SR1911 and the SA Range Officer. I got the RO for the adjustable sights and so that I could have two 1911s sighted in for different kinds of shooting.
Both have been excellent in all respects. The RO will shoot tighter groups - very tight and smooth gun, but it does have some sharp edges, especially on the safety. The SR is an ergonomic masterpiece - one of the most comfortable 1911s I've shot, yet. Not quite as tight a gun as the SA, but considering I'm up to 1500 rounds with not ONE malfunction on the gun's part, I can't complain. My SR would be the last gun I would ever sell.