I have already mentioned that a lot of reviewers appear to have enjoyed Leif's preface to 'The Ruy Lopez: A Guide for Black'. Yesterday I noticed a small article which connects a very well known Fischer game to a game from this introduction. While not exactly a review I allow myself to consider this piece a recommendation of our book. The blog in general seems interesting so I added it to my favorite chess links list.
As for the theoretical part, I am no expert on the Nimzo Indian but it seems that the debate on Spassky's 13.fxe5 is closed in Black's favor. However, after 13.0-0 0-0 a few strong players still seem to believe in White's chances after 14.f5 or 14.Qe1. But the main reason that there are so few recent games seems to be that White's set-up with e3 and Nf3 isn't very popular for the moment.