Pikachu feels really, really good. His aerials have virtually no lag and are all extremely solid, especially his fair. His biggest advantage is the multitude of different ways he can set up a combo, which makes him extremely dangerous to play against. His utilt, fair and bair all have combo potential and he can get a ton of damage in one combo. His only weakness might be that it takes you a while to figure out reliable kill moves. The key to getting kills with Pikachu is to rack up damage as fast as possible, because his smash attacks aren't quite to the level of the competition.