I thought the Tiesto one was as expected... a commercial trance interpretation. I can't be dissapointed with it because I didn't expect anything of it. Haven't heard the montana mix.
The lieb mix I thought was pretty cool. There's something just not quite right about it (in a good way). And Umek's own mix. Well he knows best what the original tune was trying to achieve and as it did the trick he was on a hiding to nothing here. The original was never going to be bettered, but at least I can now play Umek's mix without risking looking like a fool when I try to mix it in :/