Adding Stratum to the pool would most likely reduce stale shares to less than 5%.
Granted, if the stales are being caused by DDOS attacks.... then it really doesn't matter if we have a dedicated glass tube laser comms device between us and the pool... the pool simply won't respond.

It's a combination of:
- DDoS attacks themselves
- The DDoS service (which we have to relay all traffic through, so even when we're not under DDoS there is an efficiency hit.)
- Bad configs (sha256 miners) sucking up resources.
Without all of that in the mix the pool traditionally had ~3% stales. Stratum will definitely help with that when we roll it out.
Cheers.