As a general rule I find that going from 3.5 to Pathfinder is the same as going from 3.0 to 3.5 - a lot of little changes that, overall, make the game more enjoyable for me. If the original design goals were to fix the caster/melee balance issues in 3.5 then they failed, but I think that's just something you have to live with given the underlying assumptions of the game.
EDIT: And yes, summoners are currently broken as all hell.