The thing that I like least about every other smoker I looked at (aside from the cost) was the fact that the Firebox was offset, which means a lot of heat just gets lost.
You have to make more fire than you need in order to keep the temperature correct. Nothing is insulated it all. The only thermal mass you have is whatever thickness of steel it's made from. Grill area is mostly bigger than I need.
But the Smokey Mountain had none of those flaws except the lack of thermal mass.
Shipping costs haunt the price of a lot of these, unless they are light, something modest but with real mass will cost you $1,000 and up & lots of that is the shipping cost.
Being lightweight probably doesn't hurt the Smoky Mountain as much as some of the others because its design promotes thermal efficiency in several ways many others do not.
I really would like to build my own smoker, but I don't need another project right now. Then again, that doesn't always stop me.