Have you got a looper pedal? If so, do a test by recording keyboard, guitar and whatever other instruments you normally record with one at a time into your looper and listen to it play each back through your studio monitors. Then record what the looper is playing into your DAW and switch back and forth between the looper playback and the recorded playback to see if there is any difference between them. Do these recordings in mono with no effects. If the recorded playback sounds exactly the same as your looper, then you have to ask yourself, how do you improve on "exactly the same"? If you honestly do hear a difference, then yeah, upgrading may be helpful in your case.
If you want to try it in stereo also, do it at 16/48. At any resolution higher than 44.1 there probably won't be any oversampling employed, although that wouldn't likely change anything anyway. 24-bit is okay too as long as you aren't using any effects.
Bill