I built this recently:

I presume we aren't taking anything into account except for personal preference? If I could do either... of course I would go with a cockpit. I'd be surprised if anyone would prefer to not go with the cockpit.
There are 2 reasons I went with an upright cabinet for my driver.
1. Space - I didn't have room for a cockpit.
2. Games - I am only playing arcade games on mine. Arcade drivers are meant to be played quickly. Few minutes and the game is usually over. If I were building an xbox driving cabinet, I'd want it to be a bit more comfortable.
I suppose cost could be a factor, but in my case it wasn't. Since I didn't have the space and planned on playing arcade drivers - cost didn't matter.
Check out The Coders build in Project Announcement. He is going all out on a cockpit style cabinet.