Better, who knows. Seems different in that Flipflop uses P2P connections directly to the peer, alternatively via other available peers (and initial connection might use central signaling server), while taildrop seems to depend on a tailnet, which is typically hosted by Tailscale (unless you run that yourself).

I guess it's a bit like comparing WeTransfer with Airdrop, one tries to use the network they're on already (internet) where the other favors local-local connections.