I have a Vigilant and love it. I don't expect to ever want to replace it. I can have a 700 to 750 degree griddle in about 15 minutes, whereupon I switch to horizontal. When I throw the damper for a horizontal burn I get a roar through the back side exit and typically the griddle gets even hotter for a while.
Aaron, when you switch to horizontal are you still giving it a lot of air? You are familiar with the thermostat and flap at the back of the stove, aren't you?
Keep that flap open for a while to make sure the wood keeps burning well after the switch. In horizontal burn we're not really looking for a roaring flame anymore but with enough air, the stove will stay good and hot though should settle down to 450 to 500. At bed time, I totally fill the box through the griddle top. (be sure to switch back to vertical before opening either door!) Once I refill, I open the right front door about an inch to get a super draft. Soon I have a roaring fire again, just enough to char the new wood. Then I close the front door, switch back to horizontal burn, and adjust the thermostat flap to be just barely closed. I also usually close the little tear drop flap on the lower left wall of the stove.
With a final reload at bedtime (around 10:30) I'll wake up about 7:30 or 8:00 to a 350-450 degree griddle top and some pretty good hot coals. Enough to get another fire going if I want it.
Good dry wood and air. That's all you need. Don't worry about smoke. If you have a good fire, smoke will be minimal.
Do you have a Vigilant owner's manual? If not, let me know and I'll email you one.
Cheers!
Ken