VD/Ast 1.2/Zaptel 1.4/libpri1.4

I'm about to build a new cluster, and because I want to experiment with some stuff related to 2BCT/TBCT, I've been told I need to be using libpri 1.4 and hence zaptel 1.4, even though I'm using asterisk 1.2.
Is anyone who isn't Mike (:-) already doing this, and how's that workin' out for you?
Is anyone who isn't Mike (:-) already doing this, and how's that workin' out for you?