We are building a new system where latency is key. Either commercial or opensource, our goal is to have an easy to implement fix engine where low latency is key.
For Forex,swaps,NDFs, most LPs supports >10ms execution time .with default quick-fix we could achieve <170ms latency for whole chain of processes of our application(from sending message to execution on server-side). So basically it depends on your application, how it should work & who's your LP & what latency range is your aim.
You can try with Onix instead of Quick-fix, but there won't be much upgrade in that regard.Performance & latency depends on a whole lot of other things.