I'm heading to Japan from Australia for a 3 week vacation. I would hire dedicated powder skis over there, but the problem is that I ride telemark and my boots are NTN. I spoke to a few telemark folks over there and they have said I will have no chance of finding NTN binding hire skis. So I will just be buying a pair of skis from here before I go (I need some for Australian winter anyway), and hope that they will do OK in Japan.
The deepest powder I have ever been in, was about shin/knee deep, and I was using a pair of Rossignol Experience 88. I loved it, and quickly learnt how to powder ski to a fairly good competence, so I am confident I can have a load of fun on that width ski in that snow depth.
However, will there be a big difference in shin-knee deep as opposed to Niseko deep snow? Will 90mm waist still perform the same?
I am hesitating to go any wider, even for Japan, because I have to take them home and ski them in Australia for the next several years. And no, I unfortunately can't afford two pairs of skis.
Australia rarely has those nice powder days, so the majority of my skiing will be skiing resort off piste on ungroomed (but not necessarily soft) snow, with lots of features such as trees and rocks to avoid.
FYI, the skis I am looking at getting are the Atomic Theory, or the Line Prophet 90. I am trending towards the Prophets, because I think the narrower waist will be better for Australian off-piste (sometimes very icy) conditions. Riding the 88mm waist skis in powder and loving it, has eased most of the doubts about taking them to Japan.
Plus, not only is the Theory apparently suited to lighter skiers, the Theory has more of a tail rocker, which I don't really like if it means my turns will be more "sliding" or "buttery". I very much prefer a solid locked in feeling on my turns. Additionally, the Prophet should be better at chopping through all the crud and tracked out off-piste soft-snow in Aus. I just hope they will be fun in Japan...