Interesting comments on the ZF box. My suspicion would be that much of any issue is down to the programming of the box being no different to that of a BMW saloon with traction control etc. Certainly when I had a Lotus with a Toyota engine, Lotus were adamant that they could do nothing to the engine or they would lose the Toyota guarantee and have to bear the costs of engine failures themselves.I wonder if MMC have the same issue with BMW or whether its just a problem of the complexity of re-programming the gearbox.
My experience of that ZF box was on a supercharged engine in the F type as opposed to a turbo engine as in the Morgan.. Turbos always come in with a bang after a bit of lag - zero lag is impossible whatever the manufacturers pretend. Combine that with a heavy right foot and no LSD or traction control plus a short wheel base and you have a recipe for doughnuts.
The only reason for having 8 gears as opposed to 6 is economy and the eco drive to ever lower fuel consumptions but the benefit is only achieved if the box auto shifts into very high gears at very low speeds. So the difference between drifting along gearing and spirited driving can easily be 3 or even 4 gears. I dont know whether the plus 4 does this but stamping on the throttle, dropping 3 gears and bringing the turbo onto boost in a light car on a wet road with no traction control does sound like a recipe for trouble to me. Or fun if you manage to control it. At least you have the engine in a sensible place - I found in the Lotus that once it went, there was no holding back what was for all purposes a rear engined car. Polar moment of inertia. Shades of early 911s.
Once the Welsh government lets me out of jail I must try a [plus 4 . Sounds like fun to me.