Will it be worth the effort, or should I just get a better soundcard ???

A different brand of sound card isn't going to solve your ground loop problems with your audio hook ups. You need to tackle that stuff first. Start by plugging different things into different circuits if possible (instead of all into the same power strip), and see if you can swap out power supplies, too. For instance, I got ground loop noise on the car player in certain situations with one power supply but not the other.