Nginx & long poll: Best practices to reduce memory and bandwidth footprint

Question

I use nginx in this mode for BOSH and chat clients along with gzip.

location ~* /http-bind/ {       
     proxy_buffering off;
     keepalive_timeout 55;
     access_log off;
     tcp_nodelay on;
     proxy_pass http://x.x.x.x:1111;
}

Is this the best approach to managing long polling in nginx.

I also use just one worker process for altogether for web & chat (single CPU). Is that fine?