Traveler has it right, as snow conditions can vary greatly. I have MSR Evo Ascents with the tails, and they give me a lot of flexibility for the winter hiking I do in northern New England. Here I value the aggressive traction, as I am more likely to find ice and hard-pack than deep powder, particularly if I am not breaking new snow.

If I were out west and likely to encounter lots of deep powder, then I would want something with more flotation.

The Evo Ascents are a bit more rugged than the Lightning Ascents, and less expensive. The "Ascent" part is the heel lift, which I find very useful when ascending a steep grade.

Enjoy!