Having read about the Static collider x10 performance improvements in Unity5, it begs the question: Will it still make sense performance-wise to attach a kinematic rigidbody to most every static collider (like many do in Unity 4), or is the performance improvement sufficient to make this optimization moot?
Rule of thumb
if it is expected to be moved then add a “rigidbody” and make it “non-static”.
if it is not going to move during the life-time of the game then make it “static” without a “rigidbody”.
isKinematic is just a way if we want other rigidbody to affect it or not . An example of this is a sliding door that should normally act as an immovable physical obstacle but can be opened when necessary.