I found the MotP an excellent product. I have had serious concerns about whether
4e was really still a role-playing game more than just a tactical miniatures game. Both Draconomicon and now the MotP are really addressing those concerns. The book practically drips with ideas and intriguing details - the agents of Orcus scouring ruins for clues to the Raven Queen's true name, the macabre environments of the Nine Hells (and I like how the different layers of planes make sense now) and not to mention stats for nasties such as Baphomet.
It seems to me from this review that you were expecting something that you could lay out on the table and start running adventures and battles from. Well it does have good suggestions and some nice monsters. But it's aim is to provide a rich and interesting setting along with lots of interesting details and ideas. On those criteria, I think it does very well indeed. And as you said, production values are very high.