Introduction: I had lost much of my faith in 3rd Edition after The Dungeon Master's Guide, and I was praying that The Monster Manual wouldn't let me down. How could it? It was simply a compendium of monsters. I point toward the massive tome that the 2nd Edition printed, full of hundreds and hundreds of monsters, including far-fetched ones you'd never see in your campaign because they were just too wierd or so powerful it was pointless. Well, as you will see below, this obviously essential book (unless you would like to spend three months converting 2nd Edition creatures) is, too, quite lackluster.
Cover: It was obviously a book about monsters. The big, red, central eye stares out at you, and the cover looks as if it is made from dragon's skin. It's appearance isn't nearly as soft as the other two, defining this core rulebook as a book that is definitely going to contain different material than the previous ones.
Writing Style: This wasn't quite as prominent. I was very disappointed that the writers left out the ecological and sociological information about each creature that they presented in the 2nd Edition Monsters Compendium. They also fail to list every trait that the monsters have, and when it comes to certain monsters, such as oozes, they are rather ambiguous as to what powers exactly does the creature have. They organize creatures much more effectively in 3rd Edition. But there is a great deal of the feel missing in the style in which the book is presented when compared with the 2nd Edition book.
Artwork: As with the Player's Handbook, this book is gorgeous. Incredibly gorgeous. Fantastically gorgeous. Indescribably gorgeous. Somewhat inaccurate, when compared to the previous editions. It seems they are trying to alter the appearance of the game from a dank, medieval setting to a more futuristic view of the Iron Age. In other words, the artwork (as I have now come to realize), reflects the pop-culture influence on D&D. And we all know that once something becomes pop-culture, it loses its destinctiveness, individuality, and realism to enter the surreal realm of the common layman, who knows little about any one thing and is more fascinated with Britney Spears than with a 5th level elven wizard or a half-orc barbarian.
Monsters: The standard were in, metallic and chromatic dragons, orcs, goblins, but no broken ones, or mongrelmen. They had only one example of each race, not several. It was a damn shame, to be honest. The creatures are pretty-much ready-made for combat situations, but the problem is, there are so few of them. And then, the writers decided to change things around. Up until now, Kobolds have been generally accepted to be a dog-rat sort of creature. They even bark in Baldur's Gate! Now, all of a sudden, 3rd Edition arbitrarily assigns the "reptilian" aspect to them. Now, they look more like a tall compsagnathus or a pint-sized lizard man, not a rat-dog humanoid.
It was also far from complete. Githyanki and githzerai, two races that I was most looking forward to, were not present. Nor were gem dragons. All of the strange and unique dragon breeds (deep dragons, cloud dragons, brown dragons) all were absent. I'm surprised they even kept beholders! Again, they cut stuff. Why? Well, so they could include them in later books of course. Githyanki and githzerai are reprinted both in the Psionics Handbook and the Manual of the Planes (by the way, both books have inconsistencies between the two versions of the races). I'd much rather have a single representation of them in the Monster Manual and avoid all of the confusion. The types of golems they presented was a pitiful number when compared to the 2nd Edition Monstrous Compendium.
Overall: This book is actually more of an outrage than anything else. I was furious when I finished reading it. I paid $20 for a paltry number of unavoidably necessary monsters to play 3rd Edition with. I didn't have the time or energy to convert all of the 2nd Edition Monster Manual, but now it looks like I'll end up having to do it anyway. What were they thinking? That better artwork and a pretty layout would make up for the skimpy detail and dubious lack of monster material? I think not. At this point, if it weren't for The Forgotten Realms Campaign Setting, I honestly would advise any and all gamers to avoid all but the 3rd Edition Player's Handbook, and make a hybrid between the reliable and detailed 2nd Edition and the streamlined but skimpy D20 line. That way, you lose nothing from 2nd Edition, and gain all of the benefits of 3rd Edition without all of the hassle of converting data and finding your wizard went from howitzer to peashooter or that kobolds went from dog-rats to miniature dinosaurs.