+1 on the valvetronic being more than just software. We've tried to get some sort of upgrade from BMW NA (a Dinan-like boost authorized and performed by BMW for the 2012 650i vehicles), but it doesn't seem likely. A bunch of us have written letters and expressed concerns to BMW as outlined in the link below:
To BMW USA / Canada / UK / Australia ....
I bought my 650i on [date]. I paid $XXX,000 for my car. This is my n-th BMW.
I am one of many F12 / F13 650i owners globally who is pretty upset to read that the 650i is due to get a significant engine upgrade after we had our cars typically for less than one year. I understand that facelifts do happen, but not this soon. As a customer who bought my car only X months ago, I feel seriously short-changed and done in. I certainly do not feel like a valued customer, and the driver of one of your high-end cars.
I have read that the 650i will soon get an engine upgrade that includes valvetronic, lifting the power output by some 10%, known as the N63 Technical Update for V8 TwinPower Turbo Engine. This is a very material improvement so soon after the introduction of the F12 and F13.
Fortunately, I believe there is a practical and affordable solution that should go some way towards dealing with this issue. Your engineers will be able to develop a simple upgrade to the engine management software that lifts the torque curve by 8 to 10%, if they have not already done so. If this software upgrade is distributed through your global dealerships, and installed free of charge to existing 650i owners, it would go some way towards restoring my faith in the BMW brand. Technically, this should be very easy to do, as aftermarket suppliers (e.g. Dinan) have much more powerful packages available.
I look forward to your prompt response.