Grant Green was a great jazz guitarist and I really like many of his recordings. However, it would be foolish to think that every player can play in every style equally well; few can. Personally, I don't feel that Grant Green's playing in "soul-jazz", "funk", "whatever one wants to call it" style is on the same level as that of the two other guitarists mentioned, George Benson and Wes Montgomery. That's not to say that his efforts in that style were not good; simply that they weren't as convincing as those of other players playing that style. I don't know why Blue Note didn't release some of his records after recording them, but I can surmise:
Grant Green's "His Majesty King Funk" was, in fact, released the same year that it was recorded (on lp of course). This was the same time period that George Benson was making quite a name for himself with Brother Jack McDuff and his own "Cookbook". It's a good record and as Alex points out has some catchy tunes. But it's not a great record, regardless of style, and it has some problems; some of which have nothing to do with Green. The rhythm section is not as tight as others in that style and they sound a little sloppy, and Harold Vick on tenor was a bad choice imo, sounding weak and unconvincing. This record is on Verve and I have not heard the Blue Note recordings that O-10 refers to, but if this Verve recording is any indication of what some of those Blue Notes are like, I can see the powers that be at Blue Note deciding that those records simply couldn't compete in the marketplace with records and younger players like this:
https://m.youtube.com/watch?list=PL911F2BE54808509A¶ms=OAFIAVgL&v=6ILWPfmIvys&mode=N...To me, this is simply better playing in the funk/soul-jazz style, all the way around (George Benson was 21!):
https://m.youtube.com/watch?v=J-_ccqV-AdU
