I have Slow.
Ok, you can stop laughing now.
Seriously.
STOPPIT
I'm about to do some arenas with it.
SRSLY GUYS STOP LAUGHING
So why do I have Slow? I'm currently a 45/16/0 build due to getting an itch for something new, and for another reason.
Everyone has their own playstyle, whether it's active, passive, offensive, or defensive. This is fine, but the problem arises when you get TOO stuck in your own little world. For example, I tend to play very defensively. While this often works out all right, sometimes I end up going the whole fight just running around like an idiot trying to stay alive when I should be actually trying to kill the damn opponent.
Respecs into something completely different shake you up and make you rethink your strategies. I sometimes spec into a completely offensive playstyle just to make myself leave my comfort zone and play better overall.
Try this out with your own character sometime if you find yourself stuck in a rut. Shake up your gaming and you'll improve your "favorite" spec by stretching out your legs a bit and seeing what your class is capable of.