Excellent weapon with one major drawback...trigger pull is awful. Better than Glock? No Not really. BUt for teh price is a hell of a deal on a good dependable accurate polymer handgun. Right now buds has M&Ps for $439...its basically a sigma with all the querks fixed. In my opinion, M&P, XD, and Glock are all very evenly matched pistols.
So if you want to have a good gun at a good price then yes sigma is ok. But be aware that the trigger is going to leave much to be desired.