work has indeed started, a couple different systems are being tested. It's not quite en-masse, but a number of examples have been done.
Going back to this - are these different systems on the London B9TLs and native SN11XXX batch respectively?
The upgraded London ones seem to be improved performance wise (and alot more comfortable, the cab seat bases seem to have been mounted further back) whilst the 3XXs I've driven seem to be a little slower than they were before and move through the gears more quickly. Or perhaps they're the same systems just the remap/upgrade works better with the ZF gearboxes?
Of course, this could all be a figment of my imagination!