I looked very heavily at the Sequoia as well, ended up I could not use it due to being too tall for my already existing opening (had load bearing header above it)
Keep in mind the the Sequoia is a catalytic unit, that means you'll need to replace that catalyst every 3-5 years ($300-500), but easier to get secondary burn with lower quality wood and less messing around with air during the burn cycle.
Interestingly enough, I posted asking about the Sequoia and it seems that no one (on here anyway) had one to comment about it.
If you want a slightly larger unit than the northstar, look at the
Quadrafire 7100, it's made by the same company as the northstar (heat n' glo, heatilator and quadrafire all the same company, home & hearth technologies), it's basically the same exact stove (many part #'s are the same), just slightly larger and a few more bells and whistles, also more $$$$.
Most say the zone kits don't really work unless it's a very short run straight up. Do some searches for zone kits on the quad 7100 (same kit for the north star), you'll find it talked about quite a bit in here.
Our north star heats our 2400sqft home with 28' ceilings without any issue down to around 5 degrees. It's a bit strange, in a home this large with 28' ceilings, the north star cannot seem to raise temperature at all at less than 25 degrees or so, but it'll maintain 70 all day long, but won't raise temp 1 degree. In a lower ceiling house I'd imagine you'd have a really hot room where the stove was and colder room around. I dunno. It does really crank the heat out. Keep in mind, for a home that large, your gonna need some wood, we burn 3 full cords/year about, and that's only burning every other week and we don't burn during shoulder season (we have a heat pump for that). Also, I'm lazy and wont' get up in the middle of the night to load up, so the furnace runs in the AM to bring the home back to temp. Sure they advertise burn times 8-10hrs, and you'll have hot coals for that period of time, enough to light off a new load pretty easily, but in a home that large, it's stops putting out enough heat to maintain temp after about 3-6 hrs depending on outside temp.
Good luck with the decision!