I found this link to a pdf of retired Army Colonel Gerald A. Lechliter's assessment of GWB's service in the last paragraph of Nicholas Kristof's NYT article "Missing in Action". Kristof's article is only gently critical but then he posts the link (see"here") to a full pdf of Lechtiter's assessmentin the 2nd to last paragraph.
I haven't seen this pdf available anywhere else in stories or diaries. It is a long dry 32 page read but worth the time!
Kos has a quote from Lechliter here:
Bush failed to meet Guard requirements
Here is the link to Kristof article:
Missing in Action