I would imagine that with a tub that wide, there isn't a whole lot of clearance between it and the cabinet. I stopped at a Sears this weekend and checked one out. They are so cool. Also looked at the agitator version, but the version you have would seem to be more fun---and different.
You mentioned vibration. Is your machine on a concrete floor? In my warehouse apt., the washer was on regular flooring, so the washers (every one of them---the KitchenAid TL, the various WCI/Electrolux FL'ers, the Frigidaire 1-18 and the '59 Lady Kenmore) would vibrate and shake a bit during the spin cycle. In my house, the washer is on concrete, so there isn't so much as a shimmer of vibration during spin.
I'm still debating between the TOL Duet FL'er and a Cabrio (I'd have to go w/ Whirlpool, as the nearest Sears is about 70 miles away). I'm very dedicated to the FL format, but the Oasis/Cabrio would be so much fun... Decisions, decisions.