In reply to TheGeneralist: What a useful reply.
OP: I own Vipers, part of me wishes I'd got the Quarks because they feel quite a bit lighter. However, with the Vipers, you don't need to swing as powerfully because the axe is heavier. (Quarks need pick weights to make them stick on ice apparently)
But yeah, standard reply, and probably the most useful one for you:
Go to a shop with a good selection and have a swing of the axes. See what they feel like with gloves on etc. They are pretty much equally as good, it's just personal preference.
For me, the price had a huge impact as I got the Vipers cheap, which was great. Don't forget you can always order online after you've tried them in a shop, in order to get a bargain!
Mike