Yep after a certain point it's just rank. You'll get more AI followers more often. And of course you can commandeer vehicles from more people. But usually people that reach these ranks have played so long they rarely feel the need to pull out lower ranked guys just to steal a vehicle. (The only time it happens often is to save a Spawn Truck in a tight spot)

But it does help to show that a person has definitely got some time and playing experience under their belt.
It's not really about being motivated by rank or unlocks at that point, it's just basically a side effect of those that really love the gameplay and return to help the battles!

One social effect it does seem to create is lower new level guys listen a little more, or trust higher ranked players advice or map control suggestions. I don't ever worry about rank on players, but some people really put a lot of stock in it. But in the end we're all soldiers, we all die often, and we'll all be out on the front together! And usually you can trust a super high ranked player to know how to handle things a little more knowledgably.

During the Two Years I have played I think the main servers kept the same profiles the whole time until the official pre-release server reset. So I think for the most part our profiles will be around for a long time. Just don't forget your password. Write it down twice!