Very nice. Like you said TC M3, the gearbox for the E60 M5 is exactly the same as the E39 M5, so it would be a waste to get the 6MT. The gear ratios simply won't match the E60 M5's powerband. Car and driver also stated that you can't turn the DSC completely off in the 6sp manual (
read article), which is completely lame. I'm glad you opted for the 7sp SMG. Any sane person who's an enthusiast would have done the same.
P.S. You also have the 997 Carrera S?! Tell me you got that in manual though, right? haha
Great taste in cars!