I test rode a Tachyon 3.0 a month back at a local Performance and I really liked it. I was looking to replace my undersized 7.2 FX at the time and actually liked the feel of the Tachyon better. It certainly seemed like a lighter bike. I eventually got a Scattante (house brand) Cyclocross bike from the same store and love it because my body seems to like drop bars more than flat bars (more hand positions, better breathing for me anyway). However, it was a really tough decision as the Tachyon was speced really nice for the price ($450). I'm also not sure why Performance calls it a comfort bike. It is much more like a flat bar road bike/fast commuter style.

At the price range you're looking to get it at I don't think the competition is as good. It is definately a nicer bike than a 7.1 fx or something like a Quick 6. A Trek 7.5 fx better be nicer than it considering the price difference.

If you have a Performance bike shop by you, you can test ride it and if you like it the extra $50 might be worth the peace of mind as I also recieved lifetime adjustments with the bike. I'm no Performance fanboy or anything but I've just been real happy with them so far and I am not the easiest customer to make happy .