I own both a STI Guardian (9mm) and a Ranger III (.45) and love both. Very tight, smooth, and accurate. The Guardian is my favorite carry piece. Have never owned a Dan Wesson, but my impression is that they are also very fine pistols. I'm a 1911 junkie and must confess that I am an STI fan. I own ten of their pistols and have never been disappointed.
STI-Eagle(2)/Trojan(2)/Edge/Guardian/VIP/Rogue/Ranger III/Sentinel/Tactical 4.0/Escort; Remington Rand-1911A1; Ruger Redhawk/Blackhawk; Sig P238