I liked everything about MMIV. I liked the new format. I liked the dragonspawn thingies (great for a starting campaign). I like the new monsters. I liked the monsters-with classes. I liked the extra detail.
Given a choice between MMIV and MMII where I found only about 20% of the creatures were actually usable, the rest being just plain silly, poorly conceived or just plain broken, I'll take MMIV format any time.
Heck, what's not to like about a Monster Manual I can crack open in the game and start using straight away. I'd rather need less preparation time, thank you very much - and the MMIV format give me just that.
Quit whining, people. If ya don't like it, don't buy it!