Dan Neil:

Actually, if I had the M6’s as-tested, all-in price of $171,590, and I needed a swank German GT, I think I might opt for the company’s i8, a carbon-fiber future coupe with swan-wing doors and gas-electric powertrain. She’s a cool one.
 But there is an asterisk: The i8 and the Tesla aren’t geared for flights over 155 mph. If you want a car that fast that only feels electric, you want the M6.