I had no idea this book was so small until I received it, and I don't mind it at all. I have other Japan travel books by Frommer's and Fodor's so this thin book was a blessing.
Another reviewer mentioned needing a magnifying glass to read, but I can read it fine and so can my husband -- we're twenty-somethings and he wears glasses -- so I think that if you have grandchildren or existing eyesight problems then yes, it might be an issue.
For me, the bright colors behind the text were no problem. I love how colorful everything is -- EVERY page is in color. Great photos and summaries of the top "must do" attractions.
The descriptions are short to keep the size of the book down, but they list all essential info: name in english AND hiragana/kanji/katakana (really handy!), address, hours of operation, admission fees (if applicable), a URL if they have one and what train to take to what stop and even what exit to use from the station. AWESOME.
The only blemish on this otherwise amazing book is the foldout map. Mind you the map itself is helpful as heck, what with the Tokyo subway system map included, close-ups of three popular neighborhoods, every sight listed in the book listed on the map with appropriate designations (a2, d4, etc), and even helpful phrases such as "hello" and "two beers please." However, the perforation on my copy was poor and the map was glued in VERY crooked. While trying to carefully pull the map out like was intended, it pulled the cover from the back of the book. I should have just cut it with scissors in retrospect, but that was the point of the map: to pull it out easily. When I got it loose, it was difficult to pull the excess paper from the perforation. So just cut out your map out of your copy of the book and you won't have any problems!
Oh, and the super-glossy parts of the front and back covers are just slick as hell.