Actually I prefer the filling method used by the BD. I hate fill screws: they're tiny, they require a tool, and you can't do it while driving.
As for the Revel's pumping system, it's exactly the same as the BD's But maybe it holds juice better in the long run. The thing that interests me in the Revel is the glass tank - as in real glass that isn't PMMA, like the chinese BDv2 - and the ability to fill it up by carefully unscrewing the whole thing, possibly.
I've never owned a Pontus, but I've had one on loan for a day. It wasn't too bad flavor-wise really (decent, but clearly a notch under the BD though), but the vape was too cold for my taste.