Soraka has a hidden power. The power of the banana! Her Q has amazing poke early game and the heal is amazing late game. Her E is good threw out the entire game, being able to silence and snare enemy. Her heals are not amazing, but using your W to secure assists or your ult is a good way to make gold. Now why crit? No one ever sees it coming. Your playing a game and suddenly a raka is doing 800 dmg? no one ever sees it coming and its amazingly strong.

Pros:
Many forms of slows and stuns
Heal and dmg
Fast speeds into battle.
__________________________________________________________________________________________
Cons:
Your heals do very little
W dose nothing early game in lane not even worth getting.
very squishy

Both red and blue buff are very productive. For dmg and cool down. Having 2 is optimal but if you can only have 1 go for red. Late game you can easily farm rapters and wolves with static shiv and other dmg items. Stealing objectives is very easy with a E and auto.