Kinda resurrecting a semi-dead thread here, but I bought a 2013 Skandic SWT this summer.
It is EXPONENTIALLY more capable than a normal mountain sled in deep snow. It floats around on bottomless, baseless sugar snow with ease.
We had it out a month ago or so, blown-in meadow up high, 3-4' of previously unridden snow, the SWT just trundled around, mountain sleds getting stuck everywhere.
The guy I was with was on my 05 RT1000/162" track. At one point, he was directly behind me, he'd followed me in on my track. Told him to pass me and ride over there.
He barely got past the SWT in untouched snow, got the RT stuck. Partially rider error, but he does not _suck_ - he's got a few years under his belt. The RT certainly could get around that day, we had a great time on both sleds, but unless you did Something Stupid, the SWT would NOT get stuck....
He weighs ~100# less than me. The RT is ~100# less than the SWT (if not more).
I've CERTAINLY figured out how to get the SWT stuck, and the SWT won't climb straight up the same things the RT does not even flinch at (although the SWT is a better climber than I'd thought it would be).
It is a different kind of fun than a mountain sled. The deep snow, low speed capabilities are unreal, though.
Now, it is a heavy pig, it is not nimble (but better than I thought it would be), not fast (600 etec), no room for Monster stickers, but if moving around in deep snow in the backcountry is the goal, this or a WT with the taller lugs would ABSOLUTELY be the weapon of choice for me.
If you ride down it first, you can ride back up, too (to a point, I'm sure). The one thing it won't do is climb straight up something steep in totally untracked snow. It just does not have the lug height. That said, it turns out predictably and easily. It sidehills in soft snow well. Hard snow, ehhh, yikes, but not impossible.
Maybe the older Yeti chassis really were BAD, dunno, but the XU chassis SWT is surprisingly fun/nimble/agile, and if you can go backwards, you can go forwards - battering ram it forward in low gear til it starts to dig, put it in reverse, back up, hit it again. With enough time, I'm pretty sure you could make a road up pretty much anything.
The only thing I don't like about it is the lug height - not SO much from a climbing perspective, but descending on packed trails - steep catroads, this thing is terrifying. Spring conditions coming down a steep, alpine bowl, umm, yikes. It just Does Not Slow Down. Now that I KNOW that, though, and I figured it out without hitting anything, I can compensate.
In summary, from a deep snow perspective, with "not concerned about climbing," a WT or SWT absolutely crushes a mountain sled. Yes, big track mountain sleds CAN (and do!) get around in really deep woodsy stuff, but it is SO FREAKING EASY on the SWT, it is unreal.
I find it relatively comfortable on trails, too. It is gigantic, but seats two comfortably, goes faster than I need it to, shrug, I like it. If there's a deep, untracked meadow & I have to get across it, I'm taking the SWT.
Deep, untracked meadow, and I want to go do some powder turns? Ehhh, the SWT is kinda fun, too - tossup there between the RT1000 and the SWT.
The only thing that the RT does better than my SWT is go straight up a steep, deep utnracked hill. Run the RT up it, then back down, voila, send the SWT up.
I really, really like utility sleds (modern ones, anyway) for what we do (ski).