Lapti Nek would pose a huge problem, I know that. I don't know how hard the Sarlacc scene would be.
Star Wars would be very difficult indeed - you'd need to deal with Mos Eisley, and the dewback scene (which I've attempted, and that one's a lot harder than it seems like it would be), and the detention block matte painting, and ...
Yeah, there's a lot to worry about in Star Wars. Jedi would certainly be easier, but not without its difficulties.
But since this project was done for Empire's 30th anniversary, maybe Adywan will surprise us all in 2013 ...