I have a copy of it-- I haven't run it, but I've read about the first three-quarters.
It's a very odd product, associated with the general weirdness of Pendragon. In particular, it offers tremendous year-by-year detail on the progression of the Arthurian era. That's in some ways very cool, although some GMs and players will find it limiting. It does nothing to solve the essential question of "how do you make the PCs the center of the game, when the most important stuff is designed to be done by NPCs?" So you run into several situations which amount to "roll a sequence of criticals or you fail, because hey, you're not Galahad/Lancelot/whomever." There are also some bizarre "oh, you reached this point through perfectly normal gameplay? Roll a critical or die" moments. On the other hand, it provides a huge amount of background and a fairly substantial amount of canned adventures for Pendragon. If the idea of "if it's 512 then there's that battle going on over there, this side will win no matter what, but the PCs can participate and win glory" appeals, then it may work well for you. (I should be clear that there are plenty of side-quest sorts of things that the PCs can totally determine the outcomes of-- there's plenty of scenarios allowing the PCs to defeat an evil baron and take his lands or whathaveyou.)
So, if you are a big Pendragon fan and buy into the standard structure of the game (i.e. the PCs are minor to semi-important knights in Arthur's Britain, but they're not the Lancelots of the world and to a significant degree the macro structure of the history of the timeline is set, just not the details involving the PCs), it's very good. But for many people, it's terrible. You need to want what it offers, not something else.
Personally, I can't imagine running it as-is, but I might use it as a tool in running a rather different Arthurian game. Others may find that it's perfect for their needs.