As one that does not prefer dedicated flippers, I'll respond with the simplest explanation - I like functional thumbstuds or an opening hole on flippers because I would rather use those for opening the knife. When I remove a knife from my pocket, my hands is (usually) properly positioned to open the knife using the thumbstuds...to use the flipper requires a slight repositioning. Granted, that may be because flippers are a relatively new feature, and I am not inclined to relearn how I remove a knife from my pocket to accommodate a feature that isn't incorporated in the bulk of my folders.
I have a handful of dedicated flippers; but there are only a few that I carry with regularity.
As far as the Cryo II, I agree - total POS, IMO. Hated that knife - experimented on it, ground the hell out of it, and finally threw the remains in the trash.