I loved my Taurus until it was stolen, then I bought another one. I love that one too. Super reliable, and as accurate as you could expect from a pistol
The RIA is a also an Armscor made firearm. If you call it up on the net they get good marks for quality from various forums. Everyone seems to think they are a good buy for the money.
I have had the Springfield Stainless MilSpec before, paid under $600 for it and was VERY pleased with the quality of the piece. It was more of a hardball flinger but using that load it ran 100%. Never really tested it out with HP bullets much. Don't remember any problems there either though. Other than the sights, which I replaced with Millet stake ons, that one was left 100% stock. Good gun for the money.
Just my .02 but I have ALWAYS heard great things about STI products and those I have shot seemed to be "ahead of the money" regarding the obvious care taken in assembly.