Wickham's book is extremely hard to read - and as a matter of fact, I've never pulled off reading it to the end, even on the 3rd try. The issue is he's extremely meticulous, and goes on ad nauseam on methodology, on what to make of the sources he's referencing, and so forth. This is all extremely interesting, mind you. But the amount of methodological asides is such that you rapidly lose track of where you were in the narrative, and it's easy to go through a chapter without remembering what the first few pages were about, or indeed anything at all.

For the others in the series I've no idea. They've been on my reading list forever.