On the first owner builder project I went with a freestanding woodstove, with single wall pipe going up two stories before going through the roof. It pulls air from under the house. The glass door makes viewing the fire nice....
For the second build I went with a zero clearance built in airtight unit instead. I thought I'd compare the two here.
First, the woodstove.
About 1/3 the cost and easy to install. I went for maximum heat transfer. The base/hearth is a remnant I picked up from a kitchen countertop company for $50, I had to cut a hole in it for the draft right under the pedestal. If you get the downstairs comfortable, the upstairs is too hot. It's hard to figure out furniture seating around it as the 'goldilocks' spot of not too hot/not too cold is narrow and moving. I wasted a fair amount of space with the required clearances. It gets dusty in the summer and the first burn is a bit musty and smoky. Once the fire's out, it cools quickly and I think it even creates a heat sink to the outside---I've looked at it with a thermal imager on a cold morning and it's 20 degrees colder than anything else in the house.
Now for the airtight fireplace.
I went with the smallest I could find, a Bis Nova. It is very well built. It's mounted in the middle of the downstairs (Sidenote--if there is any way your heat sources can be in the center of the structure instead of an outside wall, do it. The chimney will draft better and the heat distribution is far superior) It drafts air from outside too---this is important, if you are burning the air from inside the structure you're pulling cold air in from all the cracks and windows and doors, and creating a negative pressure. It has a thermostat controlled blower that pushes the heat into the room. It's a gentler heat with all the stone thermal mass around it--heats up slower, takes a long time to cool down. It uses less wood. You can sit right on the hearth, and position chairs around it. The likelyhood of some small child or tipsy guest falling against it is much less.
I'm certain a top of the line soapstone woodstove will outperform a cheap sheet metal fireplace insert, and as with all comparisons there are exceptions and personal tastes. My two builds are identical in size only (714 sq.ft. compared to 716) and in the same area otherwise very different designs. For function and aesthetics, I'm much happier with the airtight fireplace.
Sidenote #2--- it just struck me how amateur and primitive the first build looks compared to the second.