I totally agree about the 330's being like football boots. They reckon (from their wesite) that it's the same rubber that's on the 270's but it can't be cause I have some 270's and their fine (apart from not lasting 2 minutes). Also my heel completely slips put of this shoe (the 330's) when on very steep hills.
I think they are a terrible shoe and I'd get rid. They have tried to make a mudclaw version that's more robust but have failed. Why don't they just stick a mudclaw sole on a 290 (their best shoe IMO). I saw someone wearing some 330's to do the 3 peaks at the weekend (I wore a trail shoe and so did many others as it was very dry); I bet he can't walk today!!