Hmmm interesting idea there. What would interest me most about the outcome of this poll would be if there is more than 10% of the reefers out there who use an air pump + wood frit anywhere in their system other than a skimmer. I'd be surprised if more than 10% do this.
I suspect that the evolution of the hobby, through hobbyist interest in "new and better" along with the need of designers/manufacturers to innovate and sell has caused a dramatic shift away from bubbling as a mode of CO2/O2 transport. Additionally, skimmers are very prevalent and can nearly obviate the need for these.
Another question I would pose is: what do you believe we might learn from such a poll? What would it "really" mean if less than 10% of respondents indicated they use an air stone? Does it mean it is not effective? Does it merely represent personal choice, or the power of contemporary marketing and hobby trends?
Skimmers have been all the rage for years now. They're great, don't get me wrong, but if you run a light bio-load its easy to strip the water too clean.