False. Light Side Act 1 is AMAZING.
If you do it light side, Act 1 goes like this:
You present yourself as a reasonable, sensible and rational person. You don't start fights, but you do finish them. Every Jedi you face becomes wholly confused by you. You even get the opportunity to point out the flaws in the Jedi Code and humiliate a few of them.
When you get to Nomen Karr, he refuses to accept the premise that you would be satisfied only to meet Jaesa and resolve the conflict peacefully. He comes at you again and again, at each time you strike him down. He becomes furious that he cannot beat you, and you nonchalantly outskill him at his own game.
When Jaesa comes around, you convince her that the Jedi are ignorant and that being a sith isn't all about being a mohawk sodomite trenchcoat wearer with a potato for a brain--it's just about using the force to its fullest.
It's very fun.
For Act 1, Light side is insanely amazing. It leaves you feeling like you're a sparkling diamond in a huge mudpit, and all the Jedi can do is scratch their brainwashed heads. "But.. but.. Sith are evil, rite!? He won't attack us... and he's Sith,.. uhh.. Attack him!!!" Light Sith really do make Jedi look like walking, talking hypocrits. I love it!