Is Euler's Introductio in analysin infinitorum suitable for studying analysis today? I've read the following quote on Wanner's Analysis by Its History:

... our students of mathematics would profit much more from a study of Euler's Introductio in analysin infinitorum, rather than of the available modern textbooks.
(André Weil, 1979; quoted by J.D. Blanton, 1988, p. xii)

I got the mentioned book (there is a translated version published by Springer) and it seems a nice read. The translator mentions in the preface that the standard analysis courses puts low emphasis in the ordinary treatise of the elements of algebra and also that he fixes  this defect.
My concern at the moment is that the book may be dated but André Weil said it's a worthy read, I'd like to know if someone already read Euler's book and some modern introduction to analysis to make a fair comparison. It's important to notice that although the book is a translation, the translator made some edits in several parts of the book, I guess that with the intention of making it a readable piece for today's needs.
 A: I have studied Euler's book firsthand (I suspect unlike some of the editors who left comments above) and found it to be a wonderful and illuminating book, in line with Weil's comments. You will gain from it a deeper understanding of analysis than from modern textbooks. It is true that Euler did not work with the derivative but he worked with the ratio of vanishing quantities (a.k.a. infinitesimals), which actually turns out to be a more general concept, but this is a subject for another post.
Note: we just published a detailed study of Euler that hopefully sets the record straight and vindicates Weil's hunch.
A: I was looking around the web regarding Euler's book and found the following:

The eminent historian of mathematics, Carl Boyer, in his address to the International Congress of Mathematicians in 1950, called it the greatest modern textbook in mathematics. Boyer cited Euclid’s Geometry as the greatest mathematical textbook of the classical period, perhaps of all time, appearing in over one thousand editions. For the medieval period, he chose the less well-known Al-Khowarizmi, largely devoted to algebra. But for “modern” times, Boyer made the case for Euler’s Introductio as the greatest modern textbook — and, appropriately, this time a text in analysis.

BULLETIN (New Series) OF THE AMERICAN MATHEMATICAL SOCIETY Volume 44, Number 4, October 2007
