Pinkus,I think Flg2001 hit the nail on the head..
As I have posted before, the drivers in the GH's are IMHO
far superior to the drivers in the M. The Esotar is probably one of the top two or three tweeters in the world and the Audiotechnologie mid/woof was custom built for the GH. The current unit I believe is sourced from Dynaudio ( Yes I know Skanning started both Co's) BUT and this is a real BUT the unit in the M's is not anything special.
Also, look at the ability of the GH's to bi-wire( Which is again IMHO a MAJOR plus) the M's do NOT even offer this facility.
The cost of the drivers and the x-over with bi-wire cabability is far more expensive in the GH than the M's. Frankly, I think and I have said this before; SF wanted to freshen the line and cut costs a little. This isn't the first time a company has done this and won't be the last, but if you AB the two speakers ( which I have done and which i doubt Pinkus has done) then the superiority of the GH is obvious. One last thing, just because something is new and revised doesn't always mean it's has to be better.
In audio this circumstance seems to apply frequently, however, the reviewers and the manufacturers don't necessarily want the public to know that.