Well, I read, write, and speak in both Russian and English-My mother is totally rusian, and my dad is totally english, but I think that even though english is a totally screwed up and whacked language, it is a tiny bit easier that the russian language. Both are my native tounge, 50%-50% each. Split. Even check out my name. Partly Russian. Hows that for a comparison?
I had to learn both Russian and Engsh ?cos my mother tongue is none of them. While I find Russian harder as regards to morphology for all the endings I have to remember, and for the perfective-non perfective verbal forms and uses, ... for example, listening and understanding what I heard is more difficult in English.
But of course, English is easier to me as there are more common words between Spanish and English than between Spanish and Russian. Maybe we should ask a Vietnamese what is more difficult (not a Vietcong guy educated in Moscow, of course, nor a traitor US friend).