I got an 05 doo 144 X package summit, 2 good friends (I'll call them that, they could deny it) have the same year sleds, one is a 151 and the other 144. this is wet west coast powder, cement. They are good riders and go (under most conditions) anywhere they want. Yes 159 and longer will go higher and float better. But, it takes the challenge away. It takes some skill to get a sled up a vertical mountain top in powder. after a 2-3 day cold light snow with 3-4 feet of fresh powder, yes I would like a 159. But lets face it, in 2-3 days the powder sets up and you can keep up with the real long trackers. we used to fight this one hill (area 51 as its called) to see who could get up first. One of the guys bought a 900 king Cat 162. no more fight, first one up everytime. He said its no challenge anymore, you point and go. Almost gets boring, the thrill is gone.
Yes, it still takes some skill, But when you have 13 feet of track it does make life easier. And I boondock a lot, a 6 foot track wouldn't do me. I special ordered my sled, and I picked the 144, I do wish at times thou I would have gotten the 151, but no longer. I also weigh 160 lbs on an 800, I don't really need that long of a track, I think a mountain sled should be bought by your weight. The more you weigh, the bigger the engine and longer the track.