I've got an XP2 on my 55 Gal
. . .and I LOVE IT, LOVE IT, LOVE IT . . . .so I obviously voted XP3 . . . .can't go XP wrong, my friend . . . and good luck with your tank.
We're looking into buying a house this summer, and one of the first things I want to do is an in-wall tank of at least 150 gal
. . . .let me know how things go for you!