I've skied the MX 88 in a 188cm and the MX 98 in a 194cm.
I REALLY liked the 98. It was really surprising easy to ski. the ski has a very long shovel that causes it to ski shorter than I expected. I thought I was in for a freight train and ended up with a balarina. The ski has a light feel and a fairly forgiving touch. It carved well and absolutely destroyed spring like wet granular, it's nice to ski a square tailed ski that isn't built like a Head iM103. It felt a lot like Stockli's ISO core skis, smooth and earily quiet (like skiing on velvet) yet still light and somewhat lively. I'd ski the 194 here in the east... but I'm defective.
The MX 88, less love here. The same smooth quiet feel, but something was missing. I'm not sure what I wasn't impressed by, I just wasn't really impressed. At this width I'm looking for a ski that will handle cut-up soft snow, crud and groomers at warp speed. I don't want a knife at a gun fight, I want a howitzer... this isn't a howitzer. I expected a Kastle with vertical sidewalls, a square tail and a tip cut out to be an Austrian power house, it was... I don't know, kind of bland. In short I've skied better 88mm wide skis. They do look really cool, I guess...
The 98 i liked because it was smooth light and playful for a big ski. The 88 I didn't like because it was smooth (in a soft sort of way), light ( in a 'knocked around' sort of way) and playful (in a not burly enough way). The 98 is the B Squad Rossi SHOULD have made.
Just wait until they release the MX 108... it has tip cut outs at both ends.