I've used it and like it. It sands really nice and seems to hold up well. I found it to dry with a skin you might say on it, right after you make your initial cut the stuff sands itself. It's also epoxy based so thiers quite a few advantages their compared to polyester. The only downside was that you can't use the regular polyester hardeners. It was about 50/50 at our shop on who liked it and who didn't, but most of my staff is afraid of change so I'd discredit half of their opinions!
(forgot to change accounts again, hate when that happens. It's Jimmo for anyone not up with my split personality)