Not sure what you mean by the 510 connections are different?
Overall though sounds like it works well. From what I seen on the video then you just screw/unscrew some the base part and that adjust airflow? Looks interesting, might have to be a to be purchased item. Just havent seen many review on it.
There is a female 510 connection on the Provari. For the Hippo to work, it has a piece that has a male 510 connection on one side and a female connection on the other, the piece your atty would connect too. So it is like using an adapter, then the skit screws onto this new adapter. The threads in the female 510 connector on this adapter are a bit tighter than the standard 510 connection of the Provari which changes how the air flow works, even with the Hippo ring fully open. So if you have the "air flow ring" open, the air flow of the device is still different from just using your atty on your Provari.
I realize this may sound confusing until you actually see everything the Hippo in-tales. If I get some time later, I will take some more detailed pictures so everyone can see it.