In reply to guillemsz:
I'm afraid I can't give you a personal comparison since I've not worn or reviewed the Trango Tower Extreme (I find that range very narrow). But Toby did review them some years ago, so we can give it a reasonable guess. As B3 boots vs the B2 Salewas they are going to be:
1. More rigid - if not totally rigid
2. Probably a bit less comfy on long walks, though a lot of this will be down to personal fit
3. As in, how waterproof they are? Both fully waterproof, you should not get wet feet as long as the membrane lasts (and you don't flood them in a bog). But the TTE has a synthetic upper while the OAM is suede, so I guess it's conceivable the outer layer of the Salewas could absorb more moisture over a long day in wet snow: but if you keep them well proofed I doubt this would be an issue.