I've seen somewhere (either here or in a US forum) a comparative test between PVC (as PU) (something German) and Hypapalon (I think it was ORCA but I'm not sure) material.
The results were similar and all in all there was no difference at all in either material being resistance to heat, cold, oil, fuel etc.
PVC had a bad reputation in the past.
However modern PVC materials are as good as anything else. I believe that is a fashion in Europe that most of the tubes are made by hypalon and not PVC. Zodiak and Bombard use PVC and they are doing great!!
My boat's tubes are made out of PVC and so far have no problems with it.
May I suggest that when people make statements like this material or the other is no good it would be much better for all if they can substantiate what they say with facts. Otherwise there is no use on the info.
I will try and dig out this test. I think I have saved the file somewhere and post it.