Well I have the 105 version and it has largely filled with water, until the CO2 is turned on, then the top half an inch becomes a CO2 'vacuum'.

No, my bubbles don't go up the spiral. And I don't seem to be getting a fine mist of bubbles either - the bubbles appear to only want to exit from one point in the entire ceramic disk. I've had this for a couple of months, so it's not a 'break-in' period thing.

The clips supplied with the device are completely inadequate the clips aren't strong enough to keep the diffuser attached to the side of the tank.

I'm currently on the look out for another diffuser - thinking about the Rhinox 5000...