When you use an oil-based paint you can initially expect a much better look. Oil-based stains tend to be glossy and the deck will gleam in the sun. However, when the paint starts to chip and peel, because the surface needs to be clean for repainting. Water based paints are much easier to handle.
I have used both at one time or another. I found that the oil based deck stain last longer if it is exposed to sun, then the water based. Water based takes little time to dry, but oil based takes longer and also lasts longer. It keeps it shine and doesn't fade.