My first use of NXT, shown on this site (NozeBleedSpeed's thread on NXT), followed a coat of Z5 and a coat of Z2 the weekend before. The weather was bad all week and I washed the car a couple of times, but did nothing special to prep it for accepting the NXT.
I have applied NXT over a pile of cars with Zaino on them and the results have been dramatic. No prep work except wash or quick detail, then apply NXT Tech Wax.
Here's a friend's Mini Cooper with NXT Tech Wax over multiple coats of Zaino. The paint looks wet.
You can read his comments about 3/4 of a page down here,
I've been using this new wax now for months, and if your finish is new or in excellent condition, it works great. If your finish is neglected, and you do the right prep work, NXT Tech Wax is like frosting on cake.
Mike you seem to indicate in the post that the application of NXT coupled with the polishing pad and pressue removed any Zaino that was on the car?
Also I see to remember you saying the the Deep Crystal line's Polish step was very close to Show Car Glaze (am I right or crazy) - can you do step one and two of Deep crystal and finish with NXT?