I had it done on my previous Lexus. Wasn't worth it. Only had them do it since we just had a newborn and knew I wasn't going to have a ton of time to maintain the paint. It looks great for a few months, just a like a nice wax job, but then washes away. It came with a lifetime warranty to the car, so I had them reapply it, but I had to drop the car off for a whole day for them to do it, had it done nearly quarterly for the first 2 years. Dealer was probably pissed since they have to do a complete detail to apply the coating.
After that, it was easier to just keep touching up with Zaino than having to deal with the Xzilon stuff. Since then, I've found other sealants that are better and just as easy to apply.
If you want a true protectant on your paint, find an authorized Optimum Opti-Coat dealer and have them apply Opti-Coat (aka Opti-Guard aka Opti Coat Pro) on your car.