Just to jump in here with my own opinion...
I too have listened to the Vibes, and I own the EX90's, the SL version from Japan (from Audiocubes). I love the fact that the EX90 extension can be removed for my remote. The cord is good quality too, a slick rubberish material, not the "sticky" rubber of so many other cords.
I've modded my EX90's, but even without modding they sound better than the Vibes. The ONLY thing the Vibes have over the EX90s is better isolation, they block out more noise, if that is what you're looking for.
Then again, the EX90s are not supposed to block out much noise, it's not the intention of the design.
The vibes only sound good if you like "muddy" bass, IMO. Coming straight from the standard IPod stock buds, the vibes do sound better. But they still can't touch the SQ of the EX90s, especially after a good burn-in.
But some folks dont much care for the EX90's fit. Personally, I love it, it's my most comfortable set, and I own several types of earbuds.