I have one of these but I've been meaning to get the other kind for a while, because there are some fork crowns (not that I've got any like that, mind) that the one I've got won't work with.
I am an engeneer, one of the best ways to do this and a method which is often overlooked is using a piece of wood instead of a screw driver, preferably a piece of hardwood, it won't damage the race, seat or forks, about 50x50x400 will be perfect, woods also great for fitting cups.
Use an old knife.Tap it in all the way around then once you have a gap you can use a screwdriver.
If you just use a screwdriver without creating the gap first you'll risk damage the top of the crown an/or the race itself :?
Some forks are worse than others. I took a crown race off a set of Marzocchi forks last week with minimal effort but then had to give it a good tap down to make it fit a pair of Manitou forks as the steerer has a very slight taper at the bottom end of the steerer.
...once you've got the damn thing off (screwdriver method myself) cut a slot in it with a Junior hacksaw and turn it into a split crownrace; then you'll never have any further removal woes, no matter how many times you change it
Just fitted an Origin8 Aheadset to SWMBO's Stumpy; lovely piece of kit and came with a split crown race