I'm about 250 away from maxing out DS, I am level 46 and very close to the end.
DARKSIDE IS EPIC!
I feel like a total BAMF.
This quote from my Jedi pretty much sums up the Darkside "You will fall like so many before you."
The darkside is all about gaining power to defeat all of your enemies and becoming the greatest whilst at the same time leaving no witnesses. The darkside also has a warped sense of humour.
I highly recommend the path of evil. Plus the whole white skin, red eyes, red sabre looks awesome on a republic character.