Between the Glock and the Sigma? I would say that is pretty easy. The Sigma has never been known as a reliable weapon system, and therefore is not worthy of consideration for a serious self defense gun. The ergonomics, the trigger pull, the availability of holsters,mags,sights,barrels,triggers,etc..., is just not there if you need gear or parts. The Glock on the other hand has been combat proven to be reliable "100%". If you don't like the trigger,sights,guide rod,whatever...then there are parts available for it. Besides the G19 is small enough for concealed carry and large enough for home defense, duty carry, and competition. So like I said the G19 is the only way to go between the 2.