I have considered to buy and print the do3d C-3PO files. But since they are not accurate enough to me (e.g. just count the slots at the sides of the C-3PO-head), I refrained from this idea.
Do3D's CAD is simply junk. Unprintable with bad surfacing, holes and wall thicknesses that are way too thin; not to mention their horrible customer service. Waste of money to buy from these guys.
I agree - wall thickness on Do3D was a huge issue with me. I had to increase the thickness on my Captain America Helmet in order print something I could work with.