I have a sprayer much like the ones you guys are talking about, I love it painted my house in an hour
(after triming out the windows and such, that took two days) the nozzle it came with is for spraying latex house paint right out of the bucket.
A .017 I think but you can purchase as low as a.004 nozzle for spraying stain.
Just for fun I shot an old D50 truck bed and it looked real smooth!! truck was junk anyway and full of rust holes.
I really thought about using it years before reading any of this.
BEWARE!! it does shoot ALOT of paint at once. One pass coverage two passes and run city