The really, really short version:
2,272 pages of extremely high quality fantasy.
The slightly longer version:
Lisabit already covered this series, and we feel about the same about it, so I'll let her review stand. This series features an intricate and fascinating world/magic system, an ensemble cast of compelling and interesting and flawed characters, an evolving storyline that works quite well at escalating the threat while not seeming tacked-on, a witty and entertaining writing style, and several fantastic and unexpected twists on fantasy tropes. I'm not too proud to say that the ending had me tearing up pretty bad, and the final resolution was simultaneously satisfying without being over-done, brief without feeling truncated, touching without being sappy, and open for more books without feeling like an obvious set up. I'd rate the ending as one of my favorites in any series.
There were times when the work dragged a little bit. I agree with Lisabit that the angst in the second book could have been cut in half and that would have been fine with me. The first half of the third book dragged pretty bad for me as it ventured too close to Epic Fantasy Purgatory for comfort (that being: endless marches. Everyone just moving around the board in excruciating detail, but not actually *doing* anything). One of my favorite characters (TenSoon) got the shaft, story-wise, in the third book too, which was a shame to me. I think his character's resolution could have been more meaningful if his narrative had gone another direction (West, actually).
There are also times when you'll be screaming at the characters to pay attention to some small detail, that they are making life far more difficult and it's Just So Obvious. Of course, the first time I did that I was totally wrong about it... so you might want to keep those yells bottled up lest you be embarrassed when you're wrong...
That said, I highly recommend this series to any reader of fantasy. If you are the type of person who happens to get a little *too* excited by well-executed and fiddly magic systems (in other words: if you are a tabletop roleplayer) then all the more reason why these books should immediately go onto your must-read stack. At the top.
Oh: and Lisabit is totally wrong about the "glaring plot hole" she claims to have found. Nyah. :)