I've used them all. They're all good. Everyone has a preference. I like the quality of machining on the STI, but the fact that the Wilson is barstock sways me that way. You can't go wrong with any of them, and I doubt anyone could truly argue one was head and shoulders above the rest. It almost comes down to personal preference and cost.
I will say this though. I recently put a Yost Bonitz hammer,sear,disconnector set in a friend's gun. It was advertised to be a drop in trigger job in Brownells. It was far from that, as it was excedingly heavy. I find no fault in that, as every gun is different. What I wanted to comment on was this. If you're going to replace all 3, I highly recommend the Yo-Bo parts. They are hands down the best machined examples I've seen. The only brand I cannot say I've used is Dane Burns' parts, but I can say the Yo-Bo parts are better machined than any other brand commonly available.