I've been on the tournament scene for a few years now, so I've certianly been through quite a few markers, especially the higher end ones. Despite this, I have never been a huge fan of aftermarket triggers. Untill now, that is.
I recently purchased an Alias from Rusty Glaze of Infamous (well, now XSV), and it came with a Techna Rapier on it. Let me say, I am absolutly amazed. This is by far the lightest, fastest, most comfortable trigger I've had the pleasure of using. It currently set up with only the 25g switch to return it. This allows for smooth, and quick operation, which is particularly due to the extreme light weight of carbon fiber.
The only real draw back to these wonderful goodies, is the wait. When ordering them new, each is hand made so there is typically a few weeks wait before you recieve it. This is worth it (and its slightly larger price tag), but maybe a serisous drawback to some.
I highly recommend these. I plan hopefully picking more up for my next marker. The superb performance when correctly tuned is by far the best I've seen from an aftermarket trigger.