The medium size spiral edition is the one to get. After seeing the size of the text and tables of the pocket size version, the spiral bound book was definetly a better choice because it can be read without a magnifying glass and still fits into my lab coat.
The best I had the pocket version and wanted to see if a larger version had more info or is just larger print. Don't get both as they are identical as far as I can tell. The larger one has a ring binding, so you can lay it flat and look at it. Also, for those over 40 the print is bigger. The larger one would fit in an oversize pocket, but mine are too stuffed with other stuff to fit the big version.
Sanford Guide to Antimicrobial Therapy 2008 If you have only one reference for Antibiotic therapy this should be it.Although not always intuitive in it's layout, once you find what your looking for, it offers clear instruction and sensinable alternitives. A standard for all practices.
Sanford Guide I have been using this guide as a reference for years, since I was in school. It's a great guide.