Well, in the spirit of a little feedback is better than none, I'll give some from my experience with my '05 Expedition.
I believe the 05 is good for about 70 hp, but it has a bigger pipe than the 03, so maybe expect around 60, maybe a bit more. I think the spec on the Rotax site is with the smaller pipe, I just can't remember what it is exactly. Wait, just looked, it's 57. IF you search and look at LRD's threads on here, he's done some dynoing and porting (in the Summit forum).
I am not impressed with my gas mileage, it was around 12. Now it's around 14 (mpg CAN). I went from 45 pilots to 40, and added 6.8 grams more weight to the clutch. More room for improvement there, maybe with some needle tuning. Mine has real good acceleration up to 60, slower to 70, then hits a wall. It has a bigger track than the 03 would have though.
Mine doesn't have a swaybar, but I got a used one off the classifieds, just haven't had time to put it on yet. It is quite tippy on the trails, but very easy to throw around in the powder. It is also a different chassis though.
Hope that helps, good luck!