I only disagree about the "ayu only sings"... the girl for sure don't dance, but she acts a lot...
To me, they both have a concert in the same category: They try to comunicate to people using the songs, choreography, acting and visuals... it's like... stage musical meets popstars
But I think that while Madonna really is the center (but her dancers and bandmember does has a good space to show off too) and is kind of a superwoman, in Ayu concerts, she concentrates in what she does the best (singing and acting) and let everyone on her staff doing the same...
In the end, both choices are hard... you need lots of practice to do everything Madonna does on her shows, and maybe she could not do that when she was younger 'cause it demands some skill in a lot of different areas, what demands time...
In Ayu's case, if she didn't have enough stage presence or if she wasn't good on what she was doing, it would be VERY easy to be outshined by her band and dancers... And she never is IMO
In the end, IMO, you are asking me to choose between the best pop performer in Asia and the mother of all this kind of performaces xD I prefer Ayu (she is one of my top3 pop performers alive in the world), but Madonna is REALLY amazing (top5)
By the way, I have seen all of ayu's concert dvds minus TA live and countdowns 00-01, 01-02 and 02-03
And I watched all of madonna's concert dvds minus Like a Virgin tour :B