Hi !I would definitely go with dirt one
If you don't mind a small input / advice: less ambient light (less haze) and more glow (green text from the "engines") will set an even better mood for your nice scene
(in my opinion, at least). The lighting , the base (a.k.a "ground) they both look to clean and crisp => less the studio lighting and back(ground) presence / visibility GOD SPEED
and best of luck to you!
P.S> Should you need more speed: lower max samples to no less than 2, up the ray epsilon to a max. of 0.1. Sorry if you already knew this ...