I will post some experience that I've had with a similar device, albeit with larger mesh (30x30 .013 wire 37.5% open area). It worked great for both hop types at first, with very little hop material getting through. After quite a few uses though, the holes started to plug with beer stone, turning it a nice shade of brown. My cleaning regiment was to wash the mesh with my water hose at high pressure, but the beer stone continued to stick, plugging up at least 40% of the open holes. To get the holes unplugged I used a pressure washer.
Another thing I notice with my device is that I sit it on the bottom of the kettle during a boil, and at first the wort bubbles up through just like the rest of the pot. After about 45 minutes or so, the protein starts to gather around the base, clogging any flow of wort from the boiling action. I bet the protein is at least 1/8" thick on the bottom after 60 minutes.
I will be making a new device with 28x28, .01 wire, 51% open to see if anything changes. The opening on this new mesh is .006 bigger, so I don't expect a big increase in hop material passing through.