I saw Jon Courtenay Grimwood talking about translation at a Picocon a couple of years ago. He said two things: one, that his books had to be "translated" into American by converting some of the omniscient sections into third person (I haven't had a chance to compare US and UK editions to verify this); and two, that there is at least one well-known anglophone fantasy writer whose reputation is much healthier in Europe than in the UK, because the translator improves his prose. (And not uncommonly, a translation is used as the basis for further translations, so there's a knock-on effect.)