I find its usually a bad idea. It really limits the amount of notes you see. Majority paid with some public is a good mix. Something like relayable.org that streams from other popular relays is a an option to have. nostr:npub18kzz4lkdtc5n729kvfunxuz287uvu9f64ywhjz43ra482t2y5sks0mx5sz has a nice note from yesterday of the top 25 relays. A mix of paid and free.