When it comes to Solo Stove, I'd say bigger is better. To get the smoke reduction, you have to get the fire going really good, and you can do that with even their smallest stove. But to keep the fire going without constantly tending it, you need to be able to provide a decent amount of fuel. If I'm cooking on a Solo Stove, I prefer their largest stove, the Campfire, for this very reason; it'll hold material large enough to produce coals that will stay hot a while.
If you'll keep the fire pit in one spot, definitely go bigger. I have the Yukon, and I was surprised that it doesn't hold more material than it does. Again, for the smoke reduction, you don't want the logs burning above the top rim of the fire pit. These are efficient burners, and logs do burn pretty quickly. After each use, I dump out the ashes before replacing the cover, and the Yukon's size does make this cumbersome. I've come up with the system though, where I place two large sticks (about 2" diameter) across the stones of my "normal" fire pit, then flip the Yukon upside down onto these sticks. After shaking the Yukon a little, I flip it right side up and put it back in its spot.
One thing to be aware of with these fire pits is that your fire is essentially in a topless container. Those walls do limit the amount of heat that radiates outward, and a lot of heat goes straight up. To feel much heat, you have to be pretty close to the fire pit.
If you get one, definitely get the Fire Pit Tools. I'm not sure if they still include a basic cover, but their newer "Shelters" are much better with an interior frame in the top to keep the cover from gathering enough water that it sinks to the floor of the fire pit.
pine tree on Flickr
