My favorites are the Whelen universal LAW (RIP), the SOS undercover, and the axixtechs TRI
I have zero experience with the new cannons, but I don't doubt them being bright, especially having 12 LEDs in them (double the vertex & SOS undercover). The vertex was great when it was released, because it was a new concept to have a compact LAW with multiple mounting options and the built in flasher, but IMO it is probably one of the weaker ones on the market right now...whelen seriously needs to come out with a new version of them, because a lot of the other companies took the basic, original LAW concept and made solid improvements (whereas, I don't know of any changes, if any, that Whelen has made to the guts of the vertex since they introduced them a few years back).