Somebody is getting a bit uppity..
Tuning based solely on rolling road has limitations, lets not pretend that this is state-of-the-art.
Would most people be able to tell the diffence between a custom map done on a RR and a good generic map for a car that just has the typical absolutely trivial mods of air filters, exhausts etc.
In some cases possibly, sure, but which way around ?
Serious performance cars being tuned seriously would only use RR derived maps as a starting point because of the obvious margin for error associated with the completely artifical performance environment of the car on a dyno.
The real work would be done based on an intensive live mapping process, £1800 could be the typical cost for the development of such a map (custom), including the requisite circuit testing time to properly test a map under all conditions.
Data gathered from a live custom mapping can obviously feed into the basic for a generic map, the core data would have been derived under real world conditions - real life airflow and heat impact, pump performance, liquid surge due to acceleration vectors, increased physical stress on parts, and not least - an accurate picture of extended running performance.
A good generic map would have been well tested and typically have zero "suprise factor" due to having millions of road miles logged on it since hundreds or even thousands of cars may be using it.
How many road miles of testing is done with a "while you wait" custom map?
There are modest potential gains associated with custom maps for practically identical cars, sure but there are also potential risks - largely dependent on the skill and experience of the tuner.
Personally I would prefer to use a tuner that will do extensive road testing (wired up with all telemetry) of any of their base maps, or who will do such testing for any custom mapping that I would require.
Purely RR based tuning is no substitute for live testing.
Of course RR data is a useful tool in itself, once its limitations are understood and the typical narrow focus on peak bhp is taken more usefully in a wider context.
My snotty post was in pure frustration from a mindless comment that rolling roads are useless, there are smarter people than you in the world spending vast sums of money on this equipment for no gain?
read this thread by various tuners on the subject of corruption in the mapping industry if you are interested.
Driveway tuning is simply not to be trusted blindly, get evidence.