Didn't train overseas, but know people that did. They got junior manned into it--lowest seniority in their GS class. I understand that you do all the sim training, but they bring you back to the US for the type ride. I assume they don't want to deadhead captains to France for seat support.

Is it worth it? Probably neutral. Not a vacation because as you mentioned you should be studying. But you do get per diem, so thats a nice ~$50/day? If you don't handle jet lag well it could be a major negative.