I think it's a pretty nifty idea. I got a Hekvapor clone and it functions perfectly. Pushing the drip tip once or twice wets the wicks up nicely and I'm able to use the tank till it's dry. I haven't had any issues with it leaking either which is nice.
Compared to my Magma, Venturi, or Quasar though, I don't think the flavor is very good from the Big Dripper. On three post drippers I prefer to build on the center post but with the Big Dripper you're forced to build off the negative posts, at least on mine anyway. Rewicking is kind of annoying with the raised edges and I don't like how after I get my coils lighting up nice I have to then push them down to be in front of the air holes.
I'd say the flavor is atleast better than a Kayfun, the only RBA I've ever used. And the draw is a lot nicer in my opinion so if you can compromise on flavor a bit compared to some drippers, for the convenience of a tank, it's pretty nice.