Well no doubt there is more than enough to climb in Chamonix! Of course the weather is not as good as the Cordillera Blanca, and the overall trip cost is much greater than the San Juans.
A new guidebook to the Chamonix area comes out at the end of September. The pages I have seen online look fantastic, and so this should be a good addition to the two dozen guides that are already out in English. The App version of the book is already available on the Rockfax App.