I've filed many over the years. One of the best one was when I was at PSA still. The airport took back the space we were using as a crew room to put in a store. The company, see a way to pay less rent, downsized our crew room (was about 600 square feet) to the old quiet room (was about 60 square feet). At that time the base had about 90 pilots and 70 flight attendants. During most of the day there were two or three flights getting reading to depart.
Once they put the contractually required things (computers, chairs, coat rack ect) in to the crew closet, there was barely any room for crew, so we grieved it. It went to arbitration (along with a similar grievance about the new quiet room not actually being quiet, as it was attached to the maintenance hangar break room and shared a wall with the scheduling/dispatch woman's rest room) a few months later. During the leadup to the arbitration, I was sitting a lot of airport reserve, and one day I got bored and called the city fire department and asked what the maximum occupancy of our new crew room was. They didn't have any record of it, so they sent the city fire marshall out. I met with him, and showed him the room, which he promptly certified for max occupancy of three people. This meant we couldn't actually brief a full CRJ 700 crew of four in the crew room, let alone have more than a single crew of pilots in there getting paperwork.
We introduced the fire Marshall's report as evidence during the arbitration. Hilarity ensued. Unfortunately in the end, while the arbitrator did give us a a favorable decision, didn't provide language to enforce it very well, so the company was able to make a few superficial changes (like moving a filing cabinet out) and then just do nothing else about it.