Hi there,
I would definitely recommend the Transform Shell over the Flip Shell. I have bought them both and I found that the Flip Shell will drain the battery, since it tends to turn the screen on and off and even if you push the button on top it will not stay off if the cover bounces on it. I hope they will redesign it so you have either a magnetic or velcro lock on it. The Transform Shell works well and I have also bought the leather pouch (for the belt) for when I am on the road. I just put it into the Transform Shell when in the office or at home.