deepstream.io (in difference to Meteor) isn't a full framework. The server can easily connect to a wide range of databases, caches or messaging systems. Similarly the client library can be used with React, Angular, Knockout or whatever else your heart desires.

In terms of speed, please find performance test results here http://www.deepstream.io/info/performance-overview.html as well as a test harness that allows you to replicate them.