Wouldn't order a 174" for me personally (just a 163 kinda guy).....BUT have been riding one quite a bit this year and have been totally happy with it. On the 800 Axys, the big 174 track does load that motor down a bit, take a little of the "snap" away and a little fun factor with it. Handling and sidehill characteristics are awesome, and it's a smooth ride. It lets you do things slower and park like a dumbarse (in powder, uphill) without getting stuck as easily. The front end is still light enough to wheelie over things you want to. Great for breaking trail in deep stuff. Steers poorly on hardpack (as expected)...pushes through corners and needs body english to hustle it through corners on the road. But that's no big deal...all of these newer sleds kinda suck on trails.
The only thing that bugs me a bit on the 174" .... steep (ish) downhill powder carves. The track has a lot of float, and rides high in the snow....this loads the front suspension more on a steeper downhill and puts you on your wrists a little more. Makes it a little harder to rotate to link up turns, as the rear end doesn't "set" as much in to the snow. Probably more of a "thing" for me than most riders....I suspect many wouldn't notice this.
That all said...... Rode the Axys 850 last weekend, and the new motor really breaths life in to that 174" length. Makes it more fun and it feels shorter than it is. Much quicker reacting in side-to-side movements with the new front end...between that and the added power/torque, it makes the whole thing feel like it lost weight (even tho it didn't). If that's the way you are leaning, don't think you'll be disappointed. 850 174" will be a serious unit.