I take issue with the Spur and Conti GT as well. It's impressive for its size and because I know what it stands for, but the detailing is nonexistant. Although the CLS and the Bentleys look similar in profile, it's from other angles that the difference is evident.
The Bentleys' front is just a smoothed facade, with a slot below for the bumper vents, a hole in the middle for the grille, and four round holes for shapeless lights. It's just so anonymous, it's like a bar of soap. I haven't even got started with the rear, which I consider worse than the front.
As for the CLS, love it or hate it, you can't say it's boring. The lights have a shape, and the grille is purposeful and filled with the three pointed star. The fenders are much more rakish than the constant-radius of the staid Bentleys. That the bumper has some more features also helps the CLS.
I couldn't say I hate the Bentleys, it's just that I find them ever so passionless.
The Arnage at least makes up for it with classical 'British' lines in the profile, and that big ol' chunk of a grille - upright, like a good stately vehicle's grille should be.