Good evening Wake,
I myself have a vertical. I really like it. As with any brick smoker, it holds heat really well in the winter. Once up to temp, its just smoking as usual. Best I remember there are a couple builds on our page with off set.
My input on my vertical. It take a lot of getting used to. It is a beast with its own mind. Once you figure it out, its awesome. The longer the smoke, the less fire is needed, plus the brick are putting off a lot of heat to. By the end of a 12 hr. smoke I'm usually down to just 1/2 in. splits of wood just enough to keep the fire from going out. I have used charcoal at the end for just a little heat and keep the fire going. I usually fire it with a chimney of charcoal and load it with about 3 good sticks of wood. By the time I have everything ready, its up to temp. The awesome thing about a brick smoker is, if it gets to hot, you just open the door. Bricks will hold the heat while you get the fire slowed down. You have to add wood before its needed. Its a learning curve. If you wait to add, by the time it catches your temp will start to drop. Usually not a big deal, but at the start of a full smoke, you need steady temps to get the cold mass of meat warming up. Last but not least, anything smoked over a wood fire has a flavor that can't be touched by any other device. Looking forward to seeing your build go up.
Sorry I have no input on a off set, but I'm sure someone will be along that can. My thoughts of a offset brick smoker would be that it would be more forgiving as far as heat because your fire isn't setting under your oven.