Not so sure about rankings, as I see the forum as a collaboration medium and not a competitive one. However I feel that two things could be done to make this site more useful and usable :
1. Arrange the links a little better. If from this maths forum, I need to go to the verbal forum, I can't find an easy link to use. The only way is to perhaps use the breadcrumbs which are not that easy to spot. Perhaps a link to the GMAT club forum index at the top would be more intuitive.
2. I would like to know if someone replies to the posts that I have posted on. This is useful because the posts seem to get lost, there are so many of them. I am always interested to see what other people think of my approach or if I have solved a question incorrectly and someone else provides a correct solution. Currently I can't find any way of doing this (if there is a non trivial way, I would be interested in knowing it)
This is not to take anything away from what I am finding out to be the best GMAT resource available for any price .... Keep up the good work.