After some reading it looks to me like the biggest difference is that Dashbeam uses an established peer-to-peer system (Iroh), and can operate without servers. Magic Wormhole uses servers instead of a peer-to-peer network to set up connections. Magic Wormhole requires a "mailbox" server to negotiate a connection, and may require a relay server for NAT traversal.

Dashbeam might also use a relay (I'm not positive about this - relays are described in the Iroh docs, and I don't know for sure whether Dashbeam uses them). But Dashbeam advertises NAT hole punching that might avoid use of a relay in more situations. That should lead to higher transfer rates since you're not limited by the bandwidth of a relay run as a public service.

Dashbeam doesn't use a mailbox server. The trade-off is that Dashbeam "tickets" are too long to read over the phone, or to type in by hand. Magic Wormhole's pairing codes are designed to be short for exactly those use cases.

Dashbeam has mobile apps, it look like Magic Wormhole doesn't. Edit: looks like there are mobile apps after all!

So it looks like the advantages of Dashbeam are:

• potentially faster transfers
• doesn't rely on publicly operated servers
• appeal to fans of peer-to-peer protocols
• mobile support

And the downside I see is:

• you need an existing digital channel to send a ticket to set up a connection

Compared to some other services, like Pairdrop.net, it looks like Dashbeam might not have automatic local network discovery.