We use a 24 page contract (double-spaced, clear as day text) and turnaround is always a week or more when seller asks for modifications (or gets theirs together to respond to ours -- and then respond to our critiques of their form). Usually the first turnaround incorporates most of the major differences or items that we disagree about (after we get the price and basic terms nailed down).
By contrast, turnaround on our end I try to have within one business day, sometimes two. So-called professionals are always going to take longer that the most active owner (and less time than the least motivated). Which is what you'd expect, I think.