BoatU.S. Magazine has a (rather brief) article this month (June/July) about the various types of flares and lights, giving pros and cons. The Sirius "performed below" the benchmark Orion Pyro Flare.
The Greatland green laser performed well, but the article noted that pilots are trained to fly away from lasers, The Greatland is not hazardous to pilots . . . but it is a laser. It emits its light in a fan pattern, not a narrow beam.
For a laser to work, you have to have a target.
An aerial flare can be seen from well beyond your horizon.
Basically, the message was, take what you need to be legal and take what you need to be seen.
Another comment was that a bright fiery light where you don't expect to see one will get your attention.