I learned to slap because it's fun. It's great to get into a groove with. If you're a more percussive player it will come more naturally. And it can really add to your rhythmic feel as it's so much more dependent on keeping a constant rhythm. Not many crossover skills to "normal" playing but it came in real handy when I got a gig in a cover band playing old-school Chili Peppers, FNM, RATM, etc. So if it's more an academic exercise you will have a ball with it. Put a drum loop on and slap away for hours.
