Flea - I bought a Venture about 3 weeks ago online from Dick's Sporting Goods - $215 & free shipping (strange, but they don't offer the Venture anymore)... so far, I've been very happy with it... a little tricky to set up in the wind and secure on glare ice, but with a couple of ice anchors, it holds fine.
Room inside is not that bad - it comfortably held myself (6'3" 230), my brother (5'11" 190) & his Newfoundland dog (large)... although we primarily only use it as a shelter - ie, not much jigging while sitting inside... if you're going to just use it yourself and your dog, you should be fine....
For the $$, it's worked out well for a lightweight portable... as mentioned above, it is a little bulky but I throw it in the back of my pickup... pulling it across the ice/snow is not bad.. just load all you junk on top and bungee it down..