Even if you don't eventually go for the traditional truss design, I would still recommend reading the "Obsession" manual cover to cover:
http://www.obsessiontelescopes.com/p...ons/index.html
It's a great book and full of everything you need to build a big one (including some very important phsyics regarding truss designs).
There is nothing wrong with the design with regard to optical performance, and I can unload mine, set it up, have it collimated, aligned and working faster than an EQ6 owner takes to put their tripod together!!!
Not so good if you don't have a trailer/van and ramps - they are not light, but there are plenty of hybrid designs to fix this if need be.