I just think it's the floor. It's not so unbalanced that it causes problems for other people. I just prefer my bench.
Plus, all 3 benches are next to each other, and I kind of wanted to stay away from the guy who was using the one. I don't understand how this skinny twerp was doing it, but the guy was benching over 400 lbs. The guy looked malnourished! Maybe he took a bunch of speed before he came to the gym. I can't figure out how he was lifting so much weight.