That's one of the reasons why I typically avoid English translations of books. And sometimes Portuguese ones*; dunno, the Italian ones often get better things like idiosyncratic speech. For me the difference was night and day for this book: I read it first in Portuguese (from Martin Claret's editorial house), and... well, it's a mess. The Garzanti one in Italian gets it right, though - like, Vanja sounds smart, Alëša sounds idealist, you don't just see this just through what they're saying but also how they're saying it.

And what I said above regarding idiosyncratic speech applies to other stylistic aspects.

*The major exception is, for me, Clarice Lispector. She was so fucking good at this, that reading Interview with the Vampire in the original was actually a let-down. Sadly I don't recall her translating Russian stuff.