I just got back from a short trip up to the border region of Myanmar and I was shooting my 15mm a lot. It was on my m3 and the finder fell off the camera while I was on a sketchy wooden bridge......luckily the finder did not fall through the wooden planks ....It was the first time that it has ever fallen off my camera after 7 years of usage....
well, I put it back on my camera and didn't think much of it.....then yesterday I was out shooting with it and then the finder came off my hot shoe and slid for about 6 feet on really rough pavement....needless to say, the thing has scratches all over it....when I was checking it out to see the damage, I noticed that the plastic hot shoe piece that slides into the hot shoe is cracked and "gives" in a little.....it, looks like I can glue it back into place, but I haven't tried yet....
anyways, these new metal finders look awsome......cheers, michael
just a thought here...I have always used the 15mm with my m6ttl which has "softer" tension springs/shims in the hot shoe....I know that the hot shoe in my m3 is different in that repsect.....maybe that had something to do with it....