its all very well it being cheaper, but your never going to get as good a map on the road, as you would on an RR
true. obviously dependant on the mapper. we took a car to the dyno recently that had been mapped on the road, had alot of hours spent on it(just ask chris!) which would have cost a bomb to take the time on a dyno(though you would probably map it quicker on a rr no doubt about it) and the fellas at the dyno were more than impressed with the map/afr.
but there is alot more to replicating onroad loads etc on a dyno than just taking her down the road obviously. alot of mappers tune on a rr and tweak/check on the road.
mostly it comes down to access and costs. over here to hire a decent dyno its 100quid an hour! so its easy to see why someone like nick can make money from just buying a laptop and learning an ecu! would he be in business at all if he had to buy a dyno? i doubt it.
road mapping works especially if you know someone with a wideband and technical wisdom.
rollingroad mapping works aswell - alot more professional, less time consuming, alot safer!!, but a BIG bit more expensive.
the opinions differ on this one ofcourse. but it all comes down to what is availible, how much it costs and how good your mapper is.
Phil