Just got verification that the Polish subs are pretty awful, which I kinda suspected anyway. They may still be better than nothing, but maybe not much better ;)
Anyway, I have a volunteer offering to make them better, so hooray for that!
EDIT: FWIW, I'm also suspicious of Arabic, Croatian, Bulgarian, and at least for some of the films, Turkish. I suspect Romanian and Chinese are excellent. Then again, I could be wrong about the whole lot. The problem with using random fansubs as a source is that I don't know how fluent the author was in either the language in question or in English, and if they were even trying to translate from English, or maybe just transcribing a dub. All I've got is Google Translate telling me that they are more-or-less in the approximate ballpark.