I used to be a skateborder before. Sadly I sucked, and I ate a lot of sh*t, so I gave up skating . I was a vert skater.
I've had experience with both so I guess I can say something. I use to skate but I was really only a beginner, I could pull off the odd Gymnast plant but I could never do anything too exciting. Rollerblading is something I love doing, I go rollerblading as often as I can - especially while I'm in France, in which case I go blading nearly every day. But to be honest I prefer motorbiking, it's a lot more exciting and sometimes helps me to get rid of stress - when you're on the road there's no room for error so being stressed doesn't help anyone.