Mike, my 22mm is an original and my 24mm is made of Chinaseum. So, apples and oranges maybe. But anyway, airflow is the same on both. Temperature? ... there is a subtle difference. My perception is that the 24mm MAY be cooler. And if so, I think because the larger size is a greater heat sink. However, I vape at such low wattage ... 7W on both ... warmth really isn't a factor.
ETA: I'll get an original 24mm just as soon as they become available again. Soon I hope.
I'm using a 22mm in long mode w/ a 29g Kanthal 1.6Ω coil @10 watts and the coil raised pretty high above the air hole. This is my standard coil setup on all my atty's (except for having the coil higher on the nKFL). It's such a nice combo on a Dani Mini, looks wise. But for me, I get a bit too much TH/warmth from it. I like vaping it but I have to switch off to another setup, it's not an all day vape for me.
(Dare I say it ... for me it's more like taking a drag on a cigarette than any of my other vape setups. So when I'm in the mood for a strong 'hit' it works well.)
I either have to try reducing my wattage or perhaps switch to 30g Kanthal and up the Ωs to around 2. I've been using my 'standard' setup for so long, I guess it's time to experiment a bit with the nKFL to dial it in for my taste. That or pickup a the cheaper version of the 24mm for a test drive and see if I like it better than the 22.