All 3 are good vertical units. Here is a quick comparison of price to size.
With Backwoods you could get 2 Party models for $2448, each being 22" x 23" x 47". Comes with 6 shelves each with 11 sq ft of cooking space. With both of them you would have 22 sq ft total cooking space.
With Spicewine you could get a Medium model for $2000 that is 24" x 30" x 48". Comes with 3 racks with almost 9 sq ft of cooking space. you could add more racks in this one but you would have to purchase them seperately. All told you may get about 12 to 14 sq ft of cooking space max (within reason).
With Stumps you could get an Elite Model 4 for $1995 that is 23" x 25" x 32". I don't know what number of shelves it comes with or the cooking area. It is shorter than the other two units though, so you probably won't get as much as the above options.
Now remember, all 3 of these are quality units. There are other differences between them, but these are personal choices mostly. People are happy with all of these units far as I know.
If I were going by price per square foot I would do the 2 Backwoods Party models. Most bang for the buck.
