I've spoken with four 'high quality' off-road shops, and we're not talking ... off pavement, these are the BEST in Denver, and they ALL told me that the XREAS system is one of the most advanced and reliable shock systems , they've ever seen!
Granted, there are problems on occasion. However, ALL of them said that this system is one that they'd rely on more than almost any other and for me to go as far as possible, w/o removing it.
With that said, I said to myself 'OK, if you have no problems, don't change it'. And I'll stick to that. If I do have a problem, I'll either go to straight Bilstein replacement or a lift from OME or Toytec.
When I see people bashing the XREAS system, I take it with a grain of salt... even more that one grain now that FOUR top off-road installers here in an 'off-road capital' gave their KUDOS to XREAS.
YMMV.