I still have mine fitted, I have cleaned the fliter with the K&N cleaning kit about 8 months ago, it had a few miles though it before I cleaned it btu I cant remember how many.
I had mine swapped for the second gen version shortly after I fitted it, there should be a thread on here with the details in it somewhere. The second gen one came with a better surround which had a rubber gasket on it, this has since perrished but the rest of it is fine.
I have some pics somewhere but I dont think they are on the net so cant post much at the moment as I am away from home.