Fascinating list here, quite a few on these I haven't heard, though I have been through quite a few cabinets as well as a mix of 12in and 15in MGs and HPDs. (GRF, Lockwood, HPD, Lancaster and assorted custom jobbies). I have heard MKII Cheviots though and they are lovely!
For quite a while, I really pushed back against Paul's insistence that the 12in HPD is the pick of the bunch, sticking with MGs out of habit, but I must say the Tannoy Canterbury-derived speakers he designed for me changed my opinion. In the right cabinet with the right crossover the HPDs really are the best of the lot, and they still punch their weight against current Tannoy Canterburys.