1. limited size of meat thickness on 2nd grate due to clearance issue with chamber shell;
2. access to charcoal by swing-out of 2nd food grate: severe heat loss to meat if maintenance is needed, or if a mop/mist was applied during the smoke;
3. intake/outlet vents may not give uniform charcoal burn, heat distribution or smoke due to non-symetrical positioning, which may cause erratic flows through the cooking chamber/fire box;
I just don't get that warm & fuzzy feeling when I look at the pics or the diagram. This rig may have strong limitations, and may only be suitable for certain foods, and definately would be best suited to only those individuals with very good fire/smoke management skills (so maintenance access would minimal).
It does look like it has some nice features and seems to be well built and heavy duty, I'm just not sure the good points out-weight the drawbacks.
That's my take...good luck with your search.