to lend my perspective: I'm all for ML, because it gives mainline a sense of continuity.
Time and again you see the same obstacles and resolutions with our initial thirteen, with some twists on occasion. I'm personally none too fond of this as it begs the question if any long-term momentum can be had -- the very design of these girls just works against it so much.
Beyond that, Million Live's idol variety helps sustain interest. Kotoha may as well be my counterpart.
Still, you made a compelling point with idol development, fanghail; too often do I find myself overwhelmed and
underwhelmed by the sheer amount of CG idols there is, with the bulk of them really only falling back to their gimmick. The outlier singing talents are still present, though.
In regards to fanservice? Bring it on, I say... I'm a man to like his curves, so guilty as charged.