I have the 2008 Acerbis X-Tight boots.  Previous to that I've had Fox trackers, some MSR boots and Alpinestar Tech 6 boots.  The X-tights are awesome!  I really like the racheting system for closing the boots.  No complaints so far.  They worked flawlessly at the ISDE in Greece too.
Actually, I do have one complaint - no ankle pivot.  I'm really tempted to give boots like the Sidi Crossfire or Gaerne SG-10 a try to see what the ankle pivot is like.
The Acerbis boots are way better than my Tech 6s.