The writing system can be learned in just a few hours. Transliteration can be tricky in certain instances where letters aren't pronounced as you'd think (most notably, the possessive and case ending его, which any transliteration system will put as ego, but it is pronounced yevo). You will also probably run into troubles with your a's and o's. For example, you wrote spasiba--because this is how it is pronounced. In Russian it is spelled спасибо, and thus a transliterator will generate spasibo, which could result in your mispronouncing the o in some words, which could completely change the meaning of what you're saying.