For certain applications ....
.... there may be some advantage derived from the unibobber. And as a form of indicator, whether used separately or incorporated into the fly, it will be a big advantage for a lot of folks.
What struck me, when I first saw some flies ( mostly stimulator type flies ) tied this way in a local shop is: (1) it is going to add weight to the fly; (2) it is going to add cost to the fly; and (3) why would you want one on a dry fly above the point that the fly is floating in the first place, e.g. as an indicator or the post for a parachute, especially on a fly that is reasonably visible without a unibobber ??
Not meaning to sound negative, but I also wonder about the "castability" of a fly using the unibobber, and whether a bubble of some unusual color on the fly, or above it when used to suspend a floating nymph or emerger pattern, will put down some, maybe a lot of, fish ??
I'll qualify my comments by noting that I fish moving water for trout almost exclusively - moving water from small creeks to some of the medium sized rivers in the Intermountain West. Also, I like to keep things simple, and the unibobber just kind of runs against that principle for me.
It will be interesting to see if the market for it develops to the point that it will be available over the long term. I am inclined to check them out, but more as a small indicator for certain nymph fishing situations than incorporating them into a fly either for floatation or visibility.
John