Apparently you can purchase the boost if you don't have access to the upgrades section (on lease) - by submitting a service request and it is processed manually.Makes you wonder if you pre-heated the car and battery prior to setting off what the difference would be.
The big shift away from LR was that the brakes overheat easier, and when looking at business leases, you wouldn't be able to purchase the boost package, so you'd never be able to get close to the P in good conditions at standing.
I think you'd have to be driving pretty mental, to overheat the brakes on public roads! - I like to drive quick but have only ever had brake fade on a Mk2 astra
I think the P brakes only have an extra inch of diameter, they are not cross drilled or vented? On the track certainly, but can't see it being a problem otherwise.