Wow!
My advice would be for all non-americans not to wear Levis or jeans because the yanks might be offended.

Yes a thobe and especially the nom-thoub are quite comfortable, especially for expats that have the body of a god like me (Buddha). The ghoutra is also very utilitarian as mentioned.
I am a westerner and I wore one in KSA quite often and no one ever complained. I wonder if there will be any green thobes out tonight?