Both I guess...

It's hard sometimes, 'cos yes it's good panning hats/snares/whatever a bit left or right, but can unbalance the tune if foe example you have a hat pattern that comes in a bit of the way in and it's one side and nothing comes in on the other side to balance it...

I do use panning delays and stufff quite a lot - like feed a hat pattern through a delay with left panned to three 8th notes and right panned to 5 or some such, or feed a pad or drone through a delay with an autopan on the delay so the delay drifts across the field.

Also do lots of stuff with incidental sweeps and stuff that start centred and then pan fast left then right with very few other sounds before kicking the track back in, or stuttered vocal samples that flutter between the sides.

Or double up a synth part with 2 slightly different sounds hard left and hard right...