First time I heard about it I thought "man, this really adds complexity". Using it changed my mind. Super smooth to sync a local relay in your client with the relays your user wants to use. Handling relays that don't support it becomes the hard part nostr:note1lgzwk6qg89cx8xh2tmcqss5hcv0rdsdun2tmcrmsuugha7d86qvslg6895