I've got no experience with these, nor have I any references to anywhere that's says anything bad about them. However, to throw a spanner in the works, I've just opted for the Goodyear SuperSports, which cost £452 for all 4 fitted from Costco. They're supposed to be on par with the PS4S's and so far I can't really see any difference in the two. It's a decent cost compared to the £700 PS4S's.