Depends on what you are confident with on any given day really. Banding on the hook lends itself to the pole really, although not exclusively. Where as hair rig can be used on all methods.
Banding on hook is is good for finicky feeders, where maybe you need a bit more finesse, but hair rig tends to give better hook holds because of the free position of the hook.
hair rigging saves a bit of time and is not as much faffing as banding on hook as you can use the same pellet over again.
Hair rigging can be a pain when fishing into features like stick ups or islands. because of snags, where as banding on hook is a bit neater as less prone to snagging.
I suppose if your not 100% sure of whats required on a particular peg then a combination of the both might be a good idea.