I'm a crammer too. But it's not because I procrastinate it's simply because I cannot revise the way everyone's encouraged to. I've tried, and I forget everything within a week.
I don't quite cram to the extreme of some cases further up, but I tend to stay up very very late or sometimes all night, generally for one or two nights before the exam. This is where Red Bull is a godsend. I usually catch up on sleep after the exam and get ready for the next one in the same fashion.
We all know it's not good for us, but if it's working for you and getting the grades you need then do it. It's not like you do it every day of the year, it's a two/three week period twice a year if that.
Personally, I prefer a few weeks of that than failing and having to repeat years etc. It's pretty much the lesser of two evils.