Yes Madhouse is a much better studio in terms of animation quality. I think one of the reasons the anime sucks is obviously the studio who doesn't know how to handle a series like OP and they would need to hire good animators, I think only a few of them remained, so that could explain why the animation quality dropped
There's also the pacing, I think they try too hard at stretching each chapter by coming up with new scenes etc, which ends up with one chapter being split between 2 episodes or more. That is simply too slow, but they prolly fear that otherwise they would catch up on the manga.Still it's much faster to read the chapter.
I think if they fixed the animation problem at least the anime will be appealing again, about the rest I guess they could try to pick up the pace a bit, at the risk of having to come up with more fillers...