I have been thinking about this over the past. couple of days and as Ludite has said, (Paraphrasing) "Brakes is brakes" The one thing that can throw a spanner in the works of what is a fundamentally simple system, is control interference, in our case, in the form of an ABS system.
I haven't studied the Morgan system, but using only logic, I would guess there is a high chance that the issues being experienced by owners are somehow rooted in the ABS.
No-one seems to be talking about the ABS and it is technically beyond me, but it is surely a suspect in the enquiry?