Problems with Slam bags?

yea a guy i know just got an air system from a guy that was in need of some money and the bags are slam bags and i was lookin at them and i seen it looked like seperation bubbles on the top and small cracks in the bag and i told him that i didnt think that they was any good and he prolly needs 2 get some new ones,i wonder if it might be from over pressuring them?

i was thinkin on switchin from firestones to slam rs 72s on th front of my 00 chevy fullsize ,anyone got an opinion?