Not a fail. I'm no fan of Mercedes in any way. To me, there's nothing about them that would make me want one. I've been a die hard Grand Prix fan longer than some on this site have been alive. For me to want to keep a body style of car that I think is one of the best designs GM has done in terms of body lines, that's my choice. To me, a Grand Prix is more than a car to get in and out of. It's a condition. Up until a few months ago, I owned three generations of them and they weren't trash. The Grand Prix, aside from my opinions of the latest body design, has a distinct personality. The Mercedes doesn't have it.
In summary, yes, really. I'd keep my GP over that Mercedes - hands down. There really is no comparison in my opinion.