When I first heard about Kai thought it was a Remake similar to the recent Sailor Moon Remake (not Crystal the original series where Haruka and Michiru were made to be cousins to censor their relationship). however i have seen posts that seem to indicate that the first few Sagas have been covered in less episodes in Kai.
So i am wondering what is the difference between the original Dragonball Z and Dragonball Z Kai? eg. What has been added/removed in comparison, do people bleed when their limbs get cut/ripped off (when i first saw DBZ there was never any blood)