Alot depends on what you will be using it for. I carry an Officers model (3.5 inch) High Standard/RIA mutt that I gave diddly squat for. Add a few Wilson Combat parts and some Ed brown goodness and I have a solid reliable shooter.
The Sigs are fine weapons, unfortuantely I do not have much experience in them other than what I read. I got to check one out when a feller at the range was showing off, and that's about it. Weight was balanced, light pull, probably around 4-6 lbs, crisp break. Magwell made reloads nice if you plan to run any 3-gun or speed competitions.
As possible contenders...
I've also gotten my mitts on both a Springer TRP and a SR1911. I got a chance to shoot the TRP, and at 10 yards, first time with the weapon I ran 3 rounds touching. It was also a $1500 pistol.
The SR1911 I have not fired, but I molested the ever loving heck out of it. Fine pistol as well, fit and finish are top notch, as one would expect from Ruger. Price point was competitive with a mid to upper level Kimber at around $1200. That being said I would take a Ruger over a Kimber also, I don't care for them, too many issues have surfaced with what should amount to the Honda Civic of the .45 world. (Anything you want to do to it, you can.)
Honestly, if it were my money, I would probably snag a Taurus for $550, throw another $300 at it for aftermarket goods, and have a damn nice shooter for less than $900. Which would leave money for ammo:)