For a short time about 10 years ago, I reverted back to traveling with wheels. But after having to gate check those bags on regional jets, and getting a few back with missing zipper pulls--which the airline won't pay to fix--I returned to non-wheeled bags. I've never had a problem since then.
I think it's ironic that people will come to a forum owned by a company that makes non-wheeled bags and discusses why they prefer products made by the competition. Isn't that like being invited to friend "A"'s house for dinner and telling her you prefer friend "B"'s cooking?