Having had one, I vote without. Many will disagree.
Pros:
Better weight distribution (front to rear, not necessarily top to bottom)
No interior storage taken away
Looks nice
Cons:
Decreased departure angle
Decreased rear visibility (Irrelevent if you can't see out of the back window anyway, if say, your tire is inside and blocking the window).
Weigh those in your mind to come up with the answer that is best for you.
If i was going to do one, I like this style:
Departure angle reduction isn't so bad. Rear visibility non-existent.