The rooks are a combination of both sides. Where players feel a little more involved in the overall war aspect and understand the war game better. They attract both the dog fighters and base takers from the bish and knights who get tired of either side. A lot of vet tankers and squads choose the rooks because they are little more concerned with the war effort, but also indulge in the furballing here and there.
My 2 cents: I think the Rooks can be further parsed by the time of day. Going by EST, the morning guys 6-9 am are a fun bunch, with a significant number from Europe and Asia/Pacific. They are entertaining to talk with, skilled, but are looking to maximize their gaming value by hunting for fights or defending Bish take attempts. Not so much base taking, which is understandable when there are only 8 of us in flight. As the morning changes to mid day and early afternoon, there might be some base taking, but you can be sure that we're doing everything we can to maximize contact with the other countries, be it sneaks, base attempts, or just trying to find a fight or defend. From late afternoon on, you will see more base taking attempts, but still see quality furballing opportunities.
I'd say the funnest time I have in the morning is defending against predictable attempts by Joker and his mob. But likewise some mornings it's tough to get any base taking going due to the hordes.