So here is my air filter at just shy of 31k. Looking at it , I think it validates that I hadn't perceived any performance loss . Doesn't hurt to replace it, but you open up the pleats and it looks pretty good. Now that I've took it out, the new one is going in.
Attachment 24011
I have a scope camera. When I get close to the next change, I'll be running it up and taking a look first.