I'm biased, I own the XD and the Glock, and I do not own a Sig. I have fired Sig's, love em'. Accurate, built like a Swiss watch. But from a design standpoint, I de-cock Sigs EVERY TIME I think I am releasing the slide. Great gun, bad design for my muscle memory--It's why I have no Sig's in the stable.
i voted sig because of my personal experience with all of those guns. I dont like the trigger on the XDs, I dont like the alarming rate of cops shooting themselves and otherwise accidently firing glocks (dont believe me? google it)