I swapped mine out to urethane. They were a vast improvement over the old tires, but new rubber would have been also. I did not have the same experience as Max putting them on a two wheel saw. After warming them up, they went on without much trouble. I think they are supposed to be less prone to taking a set (flat spots) than rubber. Good reason to de-tension the blade after each use.
Funny thing is we expect these manufactured products to be uniform and flawless, but they never are. I took a dial indicator to the wheels and wheels with tires on to check for runout and I can tell you the tires I bought are not consistent thickness. They were not off by a lot, but its worth checking any tire you put on for roundness.