[mandevil]

For you and me, not a problem. My wife is a medical professional and would have no clue what to do with a TGZ file.

Also, the fact that they don't mention this difference- the UI is so poorly done that you can only tell that TGZ can go an order of magnitude larger after selecting it in one drop-down and then looking at the other drop down- is a sign of how Google wants to make this as difficult as possible.