@DrTon Latency and rate are not the same thing, in particular in presence of noise. If you have a short-term disturbance and zero latency, the controller will counter-act it. If you have latency, it might actually amplify it, because its compensation comes too late. If you sample slower (e.g. 100 Hz instead of 200 Hz) you might not reject the disturbance because you've missed it, but you won't amplify it.

For the case of our system, if we had in every control loop polling (which we don't have, and I know you are aware of that and already designing it right), we would easily accumulate another 20-30 ms of latency, compared to 2-5 ms latency that an asynchronous design can achieve.

I want to properly log this for over a year already - this is something we should do some time soon, to actually prove it does what we think it does 8).