I took a test drive in the Model S Signature Performance yesterday in Santa Monica, it was a pre-production model (not a beta). There was a very noticeable noise from the inverter when punched - I must say it sounded very exciting, like a jet engine spooling up, however I really noticed the noise difference. The standard S experienced during my Fremont test drive was almost no noise, and it was driven pretty hard. The Tesla associate mentioned the noise difference between the two versions was due to the inverter working that much harder, which makes sense. Personally, I prefer the quiet of the standard S. I haven't seen any discussion of this so wondered if anyone else has noticed this?