I think the most interesting altcoins are interesting for what they do outside payment. Many people are using steem here and now (you are receiving it also for your post), but not for making a payment. Same counts for Ethereum and Bitshares for example.
I think there will never be an altcoin beating bitcoin for payments. Bitcoin is a good payment system and upgrades and applications will make it better. If an altcoin will survive it has to do something else than payments.