Yeah, I've read a few by both Tolstoy and Dostoevsky and found they were great in English. I'm sure they're much better in Russian but as someone above stated; there's simply too much time involved in learning a new language for a few specific authors - particularly when there's so many very worthy authors outside of the Russian language, as well.
I've listened pretty extensively to people who've read 'the greats' in both English and their native language; most say they are indeed, by far the best in their native language (of course) but are still extremely good (depending on the specific translation) in English. I would guess it comes down to how 'poetic' they are and aim to be, as words with specific meanings and feelings, often simply don't exist in alternate languages.
Anyway - that's not a judgement I can, or will ever be able to personally make.