The first time I read this book was about 10 years ago. I liked it a lot, so it was a natural choice for re-reading in Spanish. The book is huge - 1300 pages in the English edition. I read the Spanish one from my Palm so I don't know how many pages it would take, but I do know it too me months to finish.
I must say my impression from the past hasn't changed. "The count of Monte Cristo" is a wonderful book, one of the best works of fiction I can think of. The plot is captivating, though not in the disgustingly eye-catching way modern fiction writers use. Chapters don't end with "and then the phone ringed..." - the reader knows most of the time what's going on and what will happen, but the book is still hard to put down.
Apart from the plot, Dumas skillfully uses the large page budget to develop all the main and secondary characters in just the right way. Everyone fits into the plot artfully and the interactions are great. The plot is not the main thing here - this book is about human nature, and this doesn't change in 150 years, and makes no difference whether the character live in the USA in 2009 or in France of the 1820s.
The book does suffer from some small amount of naivete (which is typical for Dumas), but other than that I have no complaints. It is host highly recommended. IMHO every book lover must read this one, it can serve as a model for a good novel.