Basically nip-66 is a yuge upgrade to a nip-50 search app like ants.
Here’s what I found (I posted about this in nostrability repo, and also created a rejected a NIP-50 update to include NIP-66 because of the massive win of 50 x 66 combination)
-three relay nip-66 monitors are pinged, not just nostr.watch
1. ants discovers (while logged out) eight (8x) the search surface
2. nip-66 filters out ~~50% unresponsive relays ( I discovered this while benchmarking relays for outbox https://github.com/nostrability/outbox)
3. There are slightly more results returned (+8%)
4. I asked my bot to make it so that nip-66 doesn’t add a delay to results
https://github.com/nostrability/nostrability/issues/86#issuecomment-4056384849
ants pr #135 has the nip-66 update
pr #157 has the speed to first result updates
