I really enjoyed the first three books, but then I realized just how glacially slow the plot is moving - honestly the entire plot so far should have been less than one book. This whole business of juggling the character perspectives worked for a while ... but I really just don't give a *** about half of the characters! And that half got a whole book! Ugg! I'm done until the series is finished. The author spent something like 10 years putting out the last two books (4,5 I think?), and the amount of plot advanced was only that of one book - he split the book into two parts when it got too long. That is exactly the sort of thing that an editor needs to stamp down on hard - its a completely ridiculous amount of bloat! Unfortunately editors can't do that kind of thing to a successful fiction author... leading to much worse fiction.
To sum up... its a good read, but unforgivably slow and has quite obvious plot turns that just make you roll your eyes at the character's stupidity. If you like it (and I do, for all I rant), I recommend reading the history of the Roman empire complete with battle maps. I'm not kidding, its really really cool stuff! Oh, and you'll see how the island is just freaking Britain recast into fantasy * cough Hadrian cough *, again.