Cleaners in NXT will most likely remove most/some of EX-P and reduce it's durability. Personally I don't care for NXT but it's best left topping itself (2 layers for coverage not layering) and then topped with whatever you choose.
+1 on the NXT removing at least some of the EX-P. Why don't you do a small section with each and see which one looks best to you. Personally I like EX-P, but I haven't used the newer paste version of NXT, and some really seem to like it on darker colors.