I've had one since 2007. I still have it, which I suppose says something, since I traded the Glocks I've had over the past five years. Whether it says that the thing is quite useful or whether it just shows that there is little resale/trade value to one... Well maybe a bit of both.
I don't have one of the 9mm versions, so I can't compare it to that. Fits the hand better than I remember my old pre finger groove Glock 23 doing and points better. But it was a cheaper gun and it showed. Compared to other polymer makes there were sharp edges - nothing you couldn't take care of, but they were there. (A H&K USP and an FN .40 that I had were notably smoother.) The sealer type finish, of whatever sort it is, on the stainless slide also wears rather easily. The stainless on the mags meanwhile tarnishes - I have nine mags now, but one still has a stain from a drop of Coke that got in as I unboxed things.
It works, it's expendable. I kept it even after I no longer had the FN .40 that I liked better. I've shot a fair number of revolvers, I still don't like the trigger.
I'm thinking of using an aftermarket spray on finish to darken the slide - no that the two tone look is that bothersome... just that I'd rather test things out on the Sigma before moving on to something that I'd care more about.
In a grim sort of way, perhaps I do have affection of a sort for it. It's like a faithful screwdriver or hammer - it has a tool like utility to it. Can't say that I love it though, or even am truly fond of it.