The Tesla P85D stunned many last year with its neck-breaking acceleration and improved top speed. The spacious car has now gotten a firmware update which improves its 0-60 MPH acceleration time to 3.1 seconds, and increases its top speed to 155 MPH.
The MP4-12C’s top speed is much higher at 207 MPH, putting its overall performance well above that of the Tesla P85D. However, these are both production street cars, rendering the difference in top speed totally irrelevant. No speed limit exceeds 155 MPH (with a few exceptions).
To be fair, there are other factors which determine the value of a car, including build quality, ride quality, energy/fuel efficiency, among many others. However, it would be very hard to deny that the P85D is the better value — at roughly half the price, with two trunks, with enough interior room for a small family, with outstanding efficiency, and with instant torque.