I'll throw in my two cents to echo what most everyone else is saying (although, to be honest at this point it is probably too late to catch the 31 Jul deadline at most test centers).

Go with Sheppard! Six days at a little more than an hour a day = 100%. Like Gulf said, most of my test time was taken up by the 10 'validation' questions. I ran all of the charts just because I had not been exposed to them before.

BTW, if you are in Norfolk (or near Elizabeth City), the test is free for military at the CG base and I hear that the nice testing lady down there will let you stand by for a test spot. (i.e. some Sheppard guy takes 20 mins to finish, she will let you use the rest of his scheduled block to take your exam). So there may be a chance....

Hope this helps. Good luck!