This is a strange book. It has an interesting premise (plague and masques and pseudo-Victorian social mores!) but the characters aren't very interesting or finely crafted, and it's hard to care about any of them. The plot is meandering, the world not very fleshed out (I can only hope the swamp and its inhabitants are revisited in the next book, though I can't say I'll read it), and the story is just generally lacking in oomph. I do appreciate the author's attempts at being atmospheric, though.
I laughed so hard I cried. Didn't care for the chapter on her acid trip experience, though. And I have to admit, by the end of the book, I just kind of felt sorry for the author. Her life seems very hard for her to live through, but it also seems like she has a wonderful support system in place through her family. And cats. And various taxidermied animals.
Riordan is at his best when he's writing action scenes and when he's respinning old Greek/Roman/world myths into people for Percy and his friends to meet, or events to happen, or places to go. I always particularly enjoy the way he makes them fit into the present day (like the Amazon warriors running the Amazon company in a previous book, and the Justin Bieber-ish fan cult around Narcissus in this book). Annabeth's encounter with her foe (no spoilers) at the end of the book is wonderfully tense and exciting. Luckily, there's a lot of action and new myth in The Mark of Athena. Unluckily, there's also a lot of romance and angsty teenagers, which is not something Riordan is particularly good at writing. A couple chapters worth of "Percy never wanted to let Annabeth out of his sight again" or "Piper looked at Jason and thought herself so lucky" (not actual quotes, just approximations) could have been cut to create a really fast-paced, exhilarating book. As is, the book is sometimes a drag to get through.
The Brides of Rollrock Island tells the strange story of a fictional island where the mysterious witch Misskaella pulls beautiful women from the hearts of seals to be wives for the men of the island... for a price, of course. It's an interesting twist on the selkie legends of old, and the story is less a linear narrative than an exploration of this unnatural way of life on Rollrock, and the consequences that come from it. The ending was not as strong as it could have been. Also, prepare for lots of nudity and a tastefully written sex scene, if that kind of thing bothers you.
I listened to the first couple chapters on a trip across state, and I could stand to listen to any more than that. Colfer brings nothing new or exciting to the world of fairy tales, or if he does, it happens too late in the book. Nothing exciting at all happens in the chapters I listened to, and apart from a few jokes that I did laugh at, it was incredibly boring. The characters were cliched (especially the kids' teacher) and Colfer spends way too much time dumping unnecessary information on the reader/listener.
Colfer narrates the audiobook himself, and the best I can say for him is that he's crisp and clear (and sometimes, that's all you need in a narrator), but otherwise lacking in enthusiasm.
I would recommend The Sisters Grimm series in you're looking for a good fairy tale romp, and Christopher Paul Curtis' Bud Not Buddy if you want to hear a very skilled narrator (performed by James Avery).