realskiers

John, in case the Peak 84's don't quite meet the mark, have you looked at the Fischer Motive 84? Well-reviewed everywhere I've looked.  Said to have a similar feel to the Progressor 10, but wider and slightly softer, more versatile in soft snow.  Here are some posts by Dawgcatching. 

http://www.epicski.com/wiki/2011-mid-fat-ski-reviews-by-dawgcatching#user_fischer84
http://www.epicski.com/forum/thread/99308/2011-fischer-motive-84-and-motive-80-full-length-reviews

There seems to be a lot of performance built into those -- race plate, Flowflex binding, etc..  Interesting......

I agree about the iM78 -- it is an excellent ski.  I demoed a pair for a day last year at Louise, and despite a crappy rental shop tune, I really liked the feel of that ski.  Lots of power, smooth, damp, stable, seamless transitions from hard to soft snow and crud.  I really liked it.  Hope the Peak 84 turns out to be similar.  Just curious, have you tried the Head Chip 78? Seems to be the same as last year's iM78, but with a chip.