You don't need to atomize a thin deck stain. All the sprayer needs to do is get the product on the surface. It allows the product to reach nooks & crannies better than a roller, or brush. Then as Jmayspaint said, you back brush. On a deck, I just use as fine as a broom bristle I can find...preferably split bristle. My last time, I used a push broom.
Back in the day, I used to do a lot of cedar exterior siding. I added a hose nipple to a large, maybe 2 1/2 gal? metal chem sprayer, & hooked up to a compressor with the regulator set very low. Then I used a bench brush to even out on surface.
You end up with the best of both worlds that way, & spraying makes it easy to overcome gravity when doing verticals, & overhangs. The ***** is the overspray, & waste factor. On decks, there's not any major drawbacks on the horizontal surface, but foam rollers are the way to go on balusters, with an emergency brush & rag nearby.