Hi Matt
It does take longer to heat but holds longer, mine fits in a small space 8x12 it is about one quarter of the foot print so I is made with different internal dimensions, and I burn
wood pellets in a vertclal burn grate I call a m channel. No part of my stove is to hot to touch exept the marble top at full burn. That just means feeding the channel continuously till it is white hot. My burn chamber is made with fire bricks 4x8 stuck together with clay slip dirt and
water (NC clay mud high sand content) I have a 30 gallon drum so it is a smaller vertiginous but then I heat water on top so it puts out a lot of BTUs I think that answered your question with more variables but it is not from any book I just used my own demmensions and got lucky.
Mikael