In that case probably the first 15 pages aren't much use to you as they are about using D&D monsters in Iron Heroes, and Iron Heroes monster feats.
Chapter 2 is villan classes, probably not that useful, although I suppose they could be used with D&D without much/any work. They are sort of like dragon ages for key villan roles, so they scale with CR, quicker than having to design an NPC from scratch. There are three here the Champion, Demonic Minion and Demonic Knight, adding to the ones in Mastering Iron Heroes (do you own this)?
Chapter 3 (62 pages) is probably what you are more interested in, thirty monsters in all, which could probably be used with D&D without any changes. I think the only thing you need to look for is if the monster wears armour as in Iron Heroes this gives a variable DR, (having a quick look thought I don't think any actually do wear armour). I've not really looked at the book in detail so couldn't give you an opinion on if they were "good" monsters. The presentation seems to range from picture stats and abilities; to ones with more extended information like adventure ideas, cults that worship the monster, uses for it's hide, etc. It's not consistant in this regard so some monsters have just two columns of text others several pages.
The Appendix doesn't have any useful information to someone looking to use Iron Heroes monsters in normal D&D.