Ham you can't compare the 2 games they are completely different.
Republic Commando was awesome in that someone actually pulled off a good Star Wars games without lightsabers or Force Powers. The only drawback to RC for me was the length. They need to make an expansion pack for it.
JO and JA are also different. JO having a MUCH better stroryline for the SP while JA has a better fighting simulation and MP. I was hooked from the 1st day the Raven's Claw touched down on Kejim. It's too bad Academy was the end of the JK series.