I have only mapped them on RR and personally found it a breeze, very easy to get round and quick to arrive at where you want to be. To be fair it's always been on race cars (NA and Turbo) so not needed to worry too much about the pleasantries of super clean driveability under all conditions.
So far as customer service and support is concerned you will go a long long way to find better.
We recently found ourselves with an ECU failure (long story, not their fault), it broke whilst testing late on a Thursday afternoon, a phonecall later and someone despatched to Norwich for the day with ECU in hand, saw it repaired tested and back on the car by end of Friday evening ready for Sunday race. They made no promises, as obviously they weren't to know what they would find when they got it apart, but were willing to try their best in what were frankly unreasonable timescales to most industries.
Top marks to Dave and the guys, that goes an aweful long way to keeping and making customers IMO.