I have a TFV4 Mini with drip tip airflow.
What is it there for? To cool the vapor for those running moar watts
For me i used it for the 2 weeks i tried the prebuilt clapton coil i the RCA, it would have been way too warm a vape without it.
I know a few people who use drip tip airflow, young guy at my b&m was fond of the Triton, as it had drip tip airflow and he could use his high wattage capable Herakles coils in it (couldnt in the Kerakles - too hot)
I normally use temp control exclusively, so it stays closed, only ever used it with the prebuilt clapton for that short period. will probably never get opened again...