Originally Posted by KAWIDAD

The integy foam is a bit thinker and softer, allowing your fingers to "sink more" into the foam. With the foam on both wheels the integy is 1mm smaller in circumference. There is an rctech member that has a thread in the "radio and electronics" section named "reptile", I believe, that makes and sells a rubberish style wheel instead of foam. Probably going to give one a shot.
I got mine on eBay for $13 shipped. You can get them for as low as $8-$9 shipped,so you won't be out much if you didn't like