They are a challenging build since there are two chassis
I found these very easy to build, I think the two chassis idea is actually easier since there are fewer wires to route. More holes to punch for sure but its just more of the same. The only caveat I would give is the Hammonds are not consistent with their mechanical drawings. A couple of times now I have drilled and punched based on the specs given only to have the tranny not fit right. X19 is not always exactly X19.
A chassis from soundtastik would make these things ridiculously easy to build.
Don