I have 363 brains? Wow, it's been a while since I checked.
I play JO when I'm in the mood for linear storylines. Not to mention Kyle seems more human in the plotline, too: With Jaden you just go around helping everybody, but Kyle has a goal. A non-Jedi goal: Revenge. Now THAT's an interesting story. Mix in the romantic side (which should have been further developed, IMHO) and you got a killer story. They really goofed with JA.
Also, JO has some SP mods that I like. Darth Arth's ladders are fun, and Mace Windu: Party Crasher is a short but sweet level (a real FPS killer, too. I had to turn down the settings and I still never got above 20 FPS in some places.)
MP gameplay... meh, I can get better in JA, esp. with the JO levelpack for JA. But the SP gameplay keeps me coming back. Makes it a little hard to choose.