Finally finished. This is one *long* book (I read the unabridged version), and as usual, it's hard to read such an old book without the writing style making it somewhat harder.
A big part of this is because the translation available at the gutenberg project is... awful, probably because of its own age. I had read it maybe 10 years ago in a modern spanish translation that was much superior.
In any case, you can't understand, for example, Neal Stephenson, without reading Dumas first, and this one is probably Dumas' best work. It's one of those few select books everyone thinks they have read but probably hasn't.
For example, if I say "Sinbad the Sailor", does it mean anything to you in the context of "The Count of Montecristo"? No? Then you have not read it. You may have read it on comic book form, or some excerpt, or maybe cliff's notes, but you have not read the real thing.
I loved the attention to details, like concocting a reasonable way to simulate a stock market crisis (a cute usage of what's now called a "Man in the Middle" security exploit!), or how a certain character is always described in ways that make you think she's a lesbian, but without ever really saying it out loud.
All in all, a great book to have read. But I would recommend those who want to read it to investigate and find a more modern translation than project Gutenberg's.