Re: how many miles on your xfire? major problems?
I'll admit mine is still a baby at 22k. But I drive it conservatively (rarely accelerate hard, just drive fast). The only issue was the fan recall. I do have a clunking sound when closing the driver's door - I think something is loose in there and will have the dealer look at it next time it is in. The only work I have had done is an oil and filter change just before I park it in the garage for the winter.
As far as gripes, it does not shift smoothly from 1st to 2nd and the cupholder is useless. No way to use it with a 6-speed.