Interesting to hear of problems with Vibram. A few years ago having Vibram soles was a massive plus when considering what walking boots to buy, however I'm beginning to wonder if something has changed in their production methods.
A while ago I slipped, going down on one knee, on some tiles outside my local shopping centre. I was a little concerned since I was wearing a newish pair of walking shoes with Vibram soles, and if you can't trust them ouside a shopping centre, would you want to trust them in the mountains? Ok these tiles were wet, but so is Snowdonia.