Yes, the only downside to shaving with double-edged blades is traveling by air. If you're a 'carry-on only' person, you can't take blades onboard.
That said, it is the only showstopper I've run into. 😃
@ers0 I have an antique German travel safety razor with a nested handle that fits into a small square metal case. Maybe it's due to how the small metal case shows up in X-rays but I've never had a problem traveling with a single blade inside it.