I've had my R1 for six years, very pleased with it. Nice finish, good sights, accurate, and reliable. No complaints, which is more than can be said about many of the Colts I have owned. I had a Series 70 Colt for several years, also a nice gun, but when I had to pick one to keep I held onto the R1 and let the Colt go. I was getting better accuracy from the R1. A friend of mine likes the R1's so much he bought three of them in various configurations.
Only made two alterations to the R1 since I bought it. I replaced the factory grips with Ahrends Maccasar Ebony, and I installed a arched mainspring housing (Smith & Alexander). Everything else remains stock.