What? you haven't started yet? Build it!
Thanks Ron so basically I'll have a 22.5"ER and the 18.5"ER
The grates in a UDS built from a 55 gallon drum are 22.5" diameter, so each shelf has about 120 sq inches more cooking space than an 18.5" diameter grate. That's significant.
Damn Phu, that's like those Russian dolls that fit within one another.
Another thing to consider, the UDS are cool and tough looking. The WSM has a sort of sissy boy look.