There was a guy running one at FNS a few months ago, but the rear sight fell off part way through. He kept going just using the front sight. He was also shooting a revolver.
The sights are really crude! That's one thing really lacking on the rifle. I wish I could put some nice Troy Flip ups on without interfering with the folding/locking mechanism. My friend put a green laser with a tailcap switch on his.