You obviously have more experience of this than me. I have only had a few RR and a remap.
What I do know from a RR is that the map can be tested under load at all revs, dips in BHP/Torque can be detected and compensated for. Also, the fuelling can be monitored during the process so that fuelling issues can be detected and remedied.
My torque curve was quite "lumpy" before the live remap, but it was straightened out a bit by the remap.
Also, modifications can change the nature of the engine. New cams, straight through exhaust, induction etc etc.
How can you "read" all of these variables and adjust the map to suit on a driveway?
I am not saying all this as a retorical question to put down your business, I am actually interested. I have always been a RR Live remap fan, and have had this discussion with others who say your type of remap is just as good, but I just don't get it.
I fitted a tuning box to my Xsara 110hdi and it did improve things and while I had a fair idea how it worked, I had no idea what it was doing to the engine as a whole.
My take on this is that driveway chipping will probably give some improvement, but I cannot see that it is as precise as a RR session.
To me it is a bit like a doctor setting up your heartbeat without a heart monitor or putting you on a treadmill.