Never owned an Ion - alot of people in the Harmony Central KSS forum rave about it - I had a brief play with one once in a shop - I have to agree - at first pass it seems quite dead and its presets are rather dull.
Its one of those synths that seems to take a while to get into and start to exploit - Ive heard some good sounds done with it. Certainly it seems to have alot of potential, especially considering its current price.
I cant say I am even remotely tempted by one though given what I allready have
