ive heard good and bad about both. personally i prefer running rubbers cause they work good on all surfaces and i mostly run parking lot races and run in streets that can be rough in some places. to me rubber sideways last longer. plus i will wear a rubber tire till it tears. i really dont mind. i ran a rubber set for a year and it didnt bother me. but foams supposedly last a while too. ive only run one pair and they wore down fast, but i think they were soft so....