I think the barbera red - my Audi is a slightly redder shade and is a superb colour for detailing - looks amazing when done, without so many of the drawbacks of black. Gets comments EVERYWHERE.
My Saab is pretty much the same as the grey, and while its classy and sensible, its also a bit dull TBH, and I think you'll see them everywhere quite quickly, although not as clean and shiny obviously
The grey might be the better bet for resale though...