if you think it has terrible online, then you haven't done your research. i have all 3 systems, and i can say with honesty that there is no noticable difference in online interaction, other than no being able to have a party chat whilst in-game.
its not meant to be interactive like the wii, the sixaxis is just a little bonus.
if you want the exclusive games for it, then get one. if you don't, then its a waste of money.