I own the 155 2.6 and I love it. I have ridden the 3.0 and it trenched more which I didn't like. I think the variable is snow conditions. On that day we had maybe 6-12 inches of new on top of a somewhat hard layer. The 2.6 was pushing through the snow while the 3" was cutting through the hard layer (especially when punching it) and trenching into a the softer layer underneath. I suspect when the snow gets really really deep and soft the 3 inch is better but those days are few and far between.