For what it's worth, I skied my MX83s today at +1.5, +1, and +.5 -- amazing difference in performance (although +.5 wasn't much different than spec). At 1.5 and 1 they were perfectly well-mannered, and suddenly the legendary Kästle smoothness and power was revealed to me. Just a great ski, as everyone says. At 1.5 I found the tails would break loose under certain conditions -- +1 seemed to be the sweet spot.
Of course I suppose these changes are only necessary for skiers with limited skill sets .
If it makes you feel any better, I think the 188 MX 88 is too long for me, and after skiing the MX83, thought I might like it forward s bit as well. As said before,mthe Rev 90 was a dog until moving the binding forward. For anyone not really liking their Rev 85, if you're using a free flex binding, you can mount it on a head race place.... should get you the beef you want.