Couple quick questions concerning TPU and soft gel cases. 1. Which cases provides a better grip for holding the ipad? From my limited research it sounds like the TPU is more slick so it wouldn't provide as good of a grip as a soft gel case. 2. How difficult is putting either type of case in a sleeve type of enclosure? I'd like to be able to put my ipad in a sleeve case with either a TPU or soft gel case wrapped around it at the same time for added protection when needed. Will the added friction from the TPU or soft gel make this too difficult? Any info would be greatly appreciated.