I've got the T1 TREK, which is the same design as the T2('cept the artic is tougher and beefier). Its a good tent, quite stable even without the guy lines. The guy lines, I'm sure, would make it super stable, but I didn't get any extra pegs for this (I checked the contents list, and sure enough, pegs for the guy lines are not included).
As the T2 Arctic is the same design, I'd say it would be fine in windy conditions - pitched into the wind and guyed out. Nice and easy to pitch too. I pitched mine for the first time in total darkness (navigation and timings not being my strongest skills), and it was a piece of cake.
Having said that, if the weight and price of the T2 are similar to the Crux, I think the Crux would be a better buy.
Anna, check out Richard Gear's answers (if you haven't already). He's discussing the pros and cons of tunnels v's geodesics over on you right somewhere.