I think he may have been trying to say that it downshifts a lot of times when just a bit more throttle would have been sufficient. I am also annoyed by this and sometimes turn off cruise to prevent the excessive shifting. I'd like to have a "manual" mode where it just stays in the gear I select.
I don't use the basic CC for exactly this reason. It sucks, it has one mission, keep your speed as close to possible to one speed. I don't have the adaptive thing so I can't speak for it.
So when I'm towing anything resembling a TT, I use T/H, set my gear limiter to 6, and just run without CC. Humans are still better at judging speed and distances and upcoming hills or traffic slowdowns (speaking for myself anyway), and I find it much easier on the truck to just bleed off speed slowly when required, and gain speed slowly when required.
I would never tow without T/H, that's just nuts. You miss out on power and engine braking and probably other goodies like increased line pressure (though apparently the ZF's are smart and do increase pressure as needed I don't know if that's the same thing as when using T/H).
It's better to use T/H and lock out to gear 6, then to not use T/H and let the engine lug in 7th and do more shifting back and forth.
He's got it completely backwards. Use T/H always, then use the gear limiter as needed. CC is optional but will work perfectly fine if the first two steps are done first.