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.
On the dark side, Kar also attacks you repeatedly, growing closer and closer to the dark side, getting more powerful with each attack. I continued to provoke him. When I had him chained up, and Jaesa came in, the look on her face, and the sound of her voice, were great. She starts speaking off how her whole life has been nothing but lies, and wanted that to change when becoming a Jedi. I convinced her that Kar has lied to her her whole life, about the Light Side being more powerful etc.
I take back what I said about it not being nearly as amazing, going Light. That does sound good, but for me, personally, I have always liked darker fiction. And I personally am very glad that I went dark, and am very satisfied with this bit of story. Thanks for bringing that up though. It does actually sound pretty cool.