djones1911If you plan on using Shreditor 102s in the deep powder your legs are gonna be screaming, even if you mount them bitches 5cm back from center, aint gonna help alot. i know i used the Kung Fujas as my powder ski (before the shreditors came out) and i could do about 4 runs before id need an hour break to let my legs recover.
Powder skiing doesn't mean planing up on top of the snow (leaning back in this case, which is why your quads were dead and you probably had no control) . You can ski just fine on 102s, you just have to have the right technique and get "into/under" the snow. Almost like a fluid up and down motion. As mentioned before people used to ski on 70mm width skis in powder.
Granted there's a reason fatties exist now, and skiing fat skis is a blast. But even on big 130mm waist skis you aren't necessarily staying entirely on top of the snow either. It's more fun to get into it.