Yoda's a good fun character to use... but he is not a must character to have... he does however open up a lot of options in terms of play...
For min-max users... they will probably not like Yoda as he has average health and damage... That's not his strength though. His strength comes into play when you use your head and analyse the opponent and exploit their strengths for your own. If a player does that then they will enjoy using Yoda alot... However if they like seeing big damage numbers like the ones Rey, FOTP or Geo Soldier throws out... then probably give it a miss.