I've never read or played a Warhammer Fantasy product before.
Warhammer's world feels more "sociological" than many fantasy games': it's clearly a society with its own features, functions, and classes with wide gaps in wealth and status. No one in this world is merely an "individual", but always an individual in a society. Your character's career is always tied to a place in the society; but they still have reasons to go on adventures and the game offers suggestions. For example, there are limits to what doctors are allowed to do in schools, so some more enterprising types see adventuring as an opportunity to learn some nitty-gritties of physiology and anatomy in practice.
The rules are based on d100. I don't know what the first two editions were like, but this edition uses the same dice operations that I know from Unknown Armies: doubles/matches, reversals, and rerolls. I'm not usually a big fan of systems that use the d100, but this seems to work pretty well and utilize the mechanics to their full extent. WFRP even uses Success Levels in a pretty elegant way: only the number on the tens die matter. That is, if your need to roll at least 61 and you roll 07, your success level is 6-0 = 6. Success levels can be used pretty much everywhere and you can even deduce dramatic outcomes from them ("yes, and", "no, but" etc.)
There's not a lot of maths involved anywhere and any special abilities that your character may have are pretty easily understood - most of them are described with one or two sentences. In addition, the special abilities called Talents aren't dependent on one another - that is, you don't need to pick A in order to later pick B and C or D. If you like intricate character builds, this isn't for you. But if you appreciate pretty light system with more emphasis on story than mastering the mechanics, you might like this. The advancement system seems like the fiddliest bit of the game, but at least it's done between sessions.
There are some slight organisatory issues (Success Levels are mentioned before they're explained, for example) and the PDF isn't bookmarked. The organisatory issues only really matter on the first read-through, because once you grasp the basics, you know how everything works and it's easy to grasp the logic of the system. The lack of bookmarks is a shame, but at least the six-page index appears to be pretty useful.
Other than those, the book is well-edited. The text goes straight to the point and uses words effectively: it achieves both usefulness and color without wasting words. Probably my favorite are the pages on the main gods of the Empire: each one gets a page, but on that page, you get a lot of stuff on their beliefs, practices, symbols etc.
Like I said, I can't compare it to the earlier editions which I haven't read. As a stand-alone product, it feels reasonably old-school without the clunkiness of many old-school games. The system offers a lot of freedom to make the game suit your group; and it's gritty and non-intrusive but still supports fail forward. Overall, it successfully walks the path between old and new. It's a great product.
[4 of 5 Stars!]