I read a book about language learning which contains a list of languages and their difficulty to learn it.
1 to 10, 1=easiest, 10=most difficult
Chinese (Mandarin): 7 <- takes a lot time to learn it (especially the characters), pronounciation not so easy
Russian: 6-7 <- difficult grammar
So, both of them are difficult, but in another way... it's hard to compare it. Anyway, I guess you can learn Russian faster than Chinese.