bigsled,
There are two dimensions when you say "lasts long". One is SHINE lasting, the other is PROTECTION lasting.
The protection in NXT lasts a long time. It's the most difficult product to remove from pads that I have ever used; I can barely get rid of it when I want to.
The shine is more problematic, and dependent on environmental conditions. On a garage kept vanity car, it lasts a long time. On an outdoors daily driver, the shine fades faster than some other products (but the protection is still there). The NXT Spray Booster Wax was developed to directly address this issue, and IMO the fact that the products were released at the same time is an implicit acknowledgement of this phenomenon. IMO, NXT should be seen as a two part system, incorporating the Tech Wax for the protection and the Spray Wax to maintain appearance.
The Spray Wax takes a while to catch on to. There's a nice tutorial at MOL outlining how to use it successfully. I didn't like it at first, then I caught on. Basically, you spray it on the applicator rather than the car, you quickly wipe it over the surface without care for coverage or working it in, and you wipe it off with a mf towel in each hand. Keep it away from crevasses and edges, or it won't be "quick".
Tom