Yeah, I got that one. Do we know why Booker was away? Because he came back. Health/legal problems that took a year or two to resolve? Or did he just want a break?
I think these were Cannonball's best years as a player, from about 1965 up to the end. He had slowly, leisurely almost, but surely figured out all he had heard out of Coltrane standing next to him for however long that was and incorporated that into his own thing.
Best years as a player, but not always as a record-maker. I've accrued all those Capitol records, and on some of them...there's never any that don't have at least one moment (and some have considerably more than a moment), but one moment does not a record make. But unlike Kevin, I really dug Radio Nights, because it was NOT a record, Money In the Pocket from a few years ago, that was fine, probably because it never turned into a record.
So for me, this sounds like a good nexus of band/time/repertoire/non-production. Optimistic!