I don't think the M6 wheels are up to par for a $100,000 car. I've read the same in a number of magazine reviews. The M5 wheels are OK IMO. Not great, just OK. The first thing I'd do with the M6 wheels is sell them and put on a set of BBS RS-GT's. You'll get lighter, stronger, better looking wheels for close to the same price.
For me, the M6 wheels have a generic look to them . As if they come in many sizes to fit many cars , like those you see on the Tire Rack website with brand names you've never heard of . I can't quite put my finger on it as to why.