My experience may not be typical though may provide an insight.
I have an existing Adsense account and I already have some sites approved before the new approval process came into force at the end of last year. My new site (live on January 1st) was approved after 13 days in review.
The site is hand-coded to current standards and best-practices. The site does not have written articles or any large blocks of text. Due to my take on the particular niche each page (100 so far) requires user interaction via a simple form to get the required information. There is very little non-link text on each page, about 30-40 words, and one small image.
As soon as I submitted the site to Adsense the Mediapartners-Google bot visited every page twice, all in one hit. This visit pattern was repeated four times during the review process - each visit was exactly 3 days 30 minutes apart(!). Each page has had a total of 8 visits by the bot.
On the day of approval a human from corp.google.com visited the site. He landed on the homepage and looked at two other pages, though did not interact with the forms. Nor did he look at the about / privacy pages. 15 minutes later I got the approval email.
