Socket.IO author here. You might be pleased to hear as well that our focus on the next few releases is heavy on performance and making load balancing trivial. We recently made the Socket.IO parser 300% faster. The new underlying websocket server is extremely fast (check the benchmarks at https://github.com/learnboost/websocket.io/ ), and optimizations to long-polling are coming as well.
Re: Socket.io benchmarking - how many messages can you send per second?
#11Will there be 'websocket.io-client', high-performance server-side WebSockets client module, in the near future?