[A930Rocket]

I think the white will keep it brighter and more open. If you decide to finish it off, you need to decide whether to find the lowest point and make that your ceiling height, or box in the ductwork, etc. and keep the finished ceiling up. You might be able to move some ductwork to minimize the boxing in or get it around the outside to have a tray ceiling effect.

Don't forget to locate and have access to any valves, etc. above the finished ceiling. You can use an HVAC vent of various sizes to this vs a panel. Looks better to me.