Well its detractors have pointed out that it makes great clothes shopping change room music (it's funny to me how in the past 10-15 years muzak in many shops has been replaced by pop/dance).
I think I've come to regard the album as good if not better than many similar dance/pop albums out in the past few years (I like it much more than Britney, but I liked Kylie's more--at least musically--partly due to her using Stuart Price for it all--I tend to prefer albums that rely on one or two producers). As a Madonna album it sorta rates above the middle, which I'm fine with--I admit after I was so deflated by Hard Candy maybe my standards are lowered, and I've never been a huge fan of Madonna's confessional lyrics.
To bring up the age issue again:
http://flavorwire.com/272713/madonnas-mdna-where-are-all-the-elderstateswomen-of-pop "Madonna should have made a breakup album. Not some dreamy, melodramatic teen-pop breakup album, but a record by a middle-aged mother about the failure of her marriage. You can tell that she wanted to"
Oh lord. and that says it all. Has this woman heard when Madonna tries to make prolonged stabs at that kinda music? It doesn't go well. She calls the album vapid but, and I say this as a fan, Madonna's confesional lyrics themselves have always really been pretty vapid. I don't know what anyone would expect.
On the other hand, while once again, I don't wanna hear a slew of divorce songs, I think this is one of the more balanced and thoughtful comments on the (seemingly) inevitable age issue
http://beatsperminute.com/reviews/album-review-madonna-mdna/