I too have used it... Nice product, easy to use and gives a very reflective finish as you'd expect from a sealent but for me it just lacked the depth of a quality carnauba and I've yet to find a sealent that I dont want to top - just my own personal tastes here though, as I know many prefer the more reflective shine of a sealent, I prefer the deprth and warmth of a carnuaba.
As for durability, this is where the product disappointed me - it was poor. One of the reasons I would use a sealent is for its durability, but FMJ didn't deliver here for me, easily outstripped in the durability stakes by 'nuabas like #16 and 476S. Again, just my experiences of the product here, but I also got far better durability from 1Z Glanz Wax for example.
All in all, yes a nice product and one of the best looking sealents - but durability poor and price too high for me, I'd rather spend the cash on a 'nauba like Victoria Concours

.