Yep I agree with poorider, I had a decently setup IQR,
2008 800 Mono block conversion DMAX port/polish with twins set up to run Avgas (~180hp) atacc, etc
144" Ez ryde/VE Tunnel ext.
lowered front end
feethookers
etc
Granted it wasn't a 155"(it needed it badly), but yes, you would have to change everything that makes the IQR a great racing sled into a mountain sled and it still wouldn't handle as good as a pro in the deep. Its too wide and stubby. Save yourself the heartache and buy a pro and just ride it. Such a better designed mountain/boondocking sled.
It's much lighter
narrower in body panels, ski width, running boards
much better stock suspension for mountain riding, doesn't trench and doesn't weigh 76lbs(yes that is what a stock IQR skid with Ice age rails weigh!)
Better balanced and more predictable
I had issues tuning my sled, granted twins aren't the easiest to tune, but the CFI-2 motor just runs sooo consistently. I absolutely love being able to ride my sled day after day and just doing small preventative maint. before every ride (clean clutches/belt, grease, quick inspection, etc) and just riding while in the mtns instead of tinkering like I did on my IQR. I am very particular on how my sled is running, if isn't running how it should, it basically ruins the ride for me.
So while the IQR is a killer race sled, it is built for that, RACING. Can you make it into a mountain sled? Sure, but plan on doing extensive mods to get it to perform decently. OR buy a Pro and ride. Even throw a few mods on a pro and make it even better!
Hope this helps