You'll be quite pleased with that little stand... It's the same platform all their upper-end stands are based on; they basically jazz them up a little with some more padding and stuff, but you've got all you'll need right there.

I've got both the Cobra and the Viper (I've really got one bottom and the top of both; can only use one at a time) and there's not too much I can't climb. The range of tree size you ask about is generous enough; you'll soon identify which ones as way too big to even try to get the cables around. On the bottom end of the range, you'll pretty much be limited as to how small a tree you actually feel comfortable being in.