I second that 100%
I ordered GM2B from Avrukh together with the Modernized Reti (and the nice endgame book
Let me ask You, Do you Know...?).
Avrukh series totals around 1700 pages. Great books, but totally unpractical for my situation as in full time job with kids. I can work through the main lines of Avrukh, but the more detailed rinse and repeat is nearly impossible and my motivation drops for this immense task. Time which I can better use for other chess studies.
I got the Dynamic English and played the repertoire for a while with good succes.
Maybe it's the nature of a 1.c4 2.g3 opening that you can write such a small booklet, but it certainly worked great and I regard it as one of the best dense, yet very practical opening book ever.
So I think there is a demand for practical opening books. No GM Repertoire.
Yes it may have theoretical holes
Yes it does not have to be 100% up to date
It has to give you some guidelines how to play the resulting positions and the holes should be small enough that you end up with playable positions
I am going to give Demuth a try now