well ive been using one for over a year without problems,though i know some other members have had problems with them.
the only thing im disappointed about with mine is it was supposed to be a t3/t4 to4e 57 trim.
when in reality it was a 46 trim but its still good for what i was doing with it
ive come across a forum that has xs power as a sponsor and they also have an xs power rep on the boards
http://www.clubna-t.com/forums/forumdisplay.php?f=44
and seems to give out the true info on the turbos when asked