Sorry Chris "the other great advantage of the english concertina is the relative ease of playing octaves" seemingly was a quoting someone else, I don't know who.What YOU said was:"Playing octaves on the english may be easy but it is *not* difficult on the anglo"..so I can agree it is easier on the anglo but I still think the piano is better for it :-) Not much to be arguing about I think.

Yes Alan, there is a great difference between the "vertical" row layout of the english( I use to call it "longitudinal") vs the "horisontal" ( I use to call it "transversal")of the anglo and the anglo concept - (handbar and handstrap in one piece)- locks the hands so you may comfortably reach 3-4 rows at most and this is what Henrik does too since his "english" has a reduced note/button range.
What I have done is locating the hand support to the wrist part of the hand instead and using a "wrist-strap" roughly at the same position as they use to be but by combining the two a completely different situation is achieved than with the traditional wriststraps.This is demonstrated on my You Tube videos, the "handle" holds the instrument for you which neither the trad english nor the trad anglo "handles" can do.As a result a much better control is achieved and due to the fixation of the wrist instead of the mid part of the hand you can still bend and flex the hand making it possible to reach the 6-7rows(even 8 for the 64key instruments) of the common englishes.This IS the conflict to overcome with the english - combining bellows-control with enough flexibility to reach the necessary notes.