An unconventional voice technique

The Amulet of Samarkand, by Jonathan Stroud, features a main character that is a 5,000 year old djinn (genie), with the ultimate know-it-all, how-can-I-mess-up-your-life attitude.

(If you haven't noticed by now, I jabber a lot about mythical creatures. I've been overdue to feature a djinn; these "spirits of smokeless fire" are one of my top three fav critters, along with dragons and gryffins.)

Bartimaeus, this djinn full of delicious attitude, already has a strong voice. But the author uses an unconventional technique to ramp up the voice even more. Here's an excerpt in the first chapter (no spoilers) where an inexperienced 12 year old magician is foolish enough to summon Baritmaeus:

You don't often get small ones like this squirt calling up entities like me, in the first place. The kid cleared his throat. This was the moment. This is what he'd been building up to. He'd been dreaming of this for years, when he should have been lying on his bed thinking about racing cars or girls. I waited grimly for the pathetic request. What would it be? Levitating some object was a usual one, or moving it from one side of the room to the other. Perhaps he'd want me to conjure an illusion. That might be fun: there was bound to be a way of misinterpreting his request and upsetting him.(3)

That (3) is a superscript (my html skills were unable to duplicate this in true stunning superscript form). The superscript references the following footnote:

(3) One magician demanded I show him an image of the love of his life. I rustled up a mirror.

The book is FULL of footnotes. It's got more footnotes than a phd dissertation.

And I had a blast reading it (without any flashbacks to college research papers). Many of the scenes are written in the young magician's point of view (no footnotes) and he's a bit of a melancholy character, so I was always happy to get back to the point of view of Bartimaeus with his endless bottom-of-the-page quips (there's at least one footnote for every three pages of Bartimaeus). I thought it was a powerful method to ramp up the character's voice without overwhelming the plot by hanging too many fanciful ornaments on it.

But I was curious what other readers thought of this unconventional method, especially the target 9-12 year old age range for this book. You can't tell the age of reviewers on Goodreads (thank heavens for that, in my case) but I did notice that quite a few reviewers didn't like all the footnotes. Some mentioned that they were distracting and made the book hard to read, constantly having to jump down to the bottom of the page and then find your location in the text again.

What do you think? Do you enjoy skipping up and down the page to enjoy funny anecdotes in a strong voice? Or would you rather sacrifice some voice for a "smoother" reading experience? And has anyone run across any other unconventional methods for developing voice?

P.S. C.A. Marshall posted statistics on genre that entered for her "win a free professional edit" contest. Really interesting results broken down by adult, YA and MG and includes number of boy MCs vs. girl MCs.

P.P.S. I finished and reviewed Like Mandarin, by Kirsten Hubbard, and it's wondddddddddderful (all the d's means it's spreading wonderful germs). There's a mythical creature in this book, too! Really! I contest that it should be listed as paranormal YA instead of contemporary YA. Here's proof:

I wished for the power to destroy whatever monster made her sabotage herself. If one even existed. Maybe it was Mandarin's official mythological creature.