M21 is sort of the pro version of NXT. Application and removal are both a piece of cake - it's in liquid form only so using a foam applicator pad makes it easy to apply a very thin coat. Once you get that thin coat down and let it haze, removal is very simple. I use this stuff a lot and have never had an issue with it. I highly recommend you get the M21 2.0 though, the new stuff.

 

Great News! I solved my SG problem. There was no problem. I believe the spots were on the car to begin with. Once I removed them using the Swissvax Cleaner (Polish) and reapplied the AIO and the SG the finish looks like glass. Still a few fine scratches where I rubbed too hard trying to get the spots out on the hood when I thought it was the SG. This car was a leftover 2005 that I bought last November. This was the first wax job that I gave it. Sitting somewhere for almost 3 years gave it the spots and the dealer just waxed over them. I didn't notice till after I put a deep finish on it. I am relieved and plan on putting two coats of SG on after it cures out.
Thats my story and I'm sticking to it!!!

 

Take a true polish and a buffer and those water spots will come out. Please check-out my "How to detail a crossfire" thread. Good to see you finally succeeded.