I don't understand what you people are talking about...
I've been using GC for approx. 5 months - in that time I've only done 2 complete applications on my car (the 2nd time was only because I had a spare afternoon, not because it actually needed it). The durability and shine is excellent - after every wash, the car still looks great. I wash my car at least once-a-week, so it can't be easily stripped off by washing. As for "very hard to remove" you're either applying too much or you're joking!
Now I'm not saying GC is the best "polishing wax" out there, far from it - I know there are many waxes out there that will give a deeper and wetter looking shine, but I just don't believe it deserves this so-called "bad reputation".
You guys in the U.S. are very lucky, because you have so many excellent car care products available to you. I just wish it was the same over here in the U.K. GC is one of the best readily available waxes over here - if we want to try products such as Zaino or Klasse we have to order it from U.S. websites and then get hit by taxes, VAT, import duties etc. when we receive over here.
I am going to be trying the P21S products shortly as they are available at a few select web retailers in the U.K. One day I'll get round to posting some pics so you can see the GC shine I get on my car - I'm sure you'll all approve!!