The contents of this book looks a lot more "AD&D" than the original MM (which felt just plain "wrong" to me with monsters such as chuul, ravid, krenshar, digester, ethereal filcher, delver, choker, athach, rast, destrachan, howler, gray render, yrthak, tojanida....mmmm, I think the cthulhu/planescape aesthetic bias of the core designers was showing through there to the detriment of the game's classic D&D feel). Between this and the ToH, 3E is finally catching up with it's predecessors in the monster stakes in book form.
Ahhh....