Have just replaced stock PSU with Corsair AX1200i and overclocked a miner to 218 MHz. Seems to be OK, without any significant HW/rejects.
Does anyone know how to avoid resetting of configuration files during reboot?.. Copying it to /etc folder doesn't help at all, anytime I shutdown or reboot my S2 I forced to configure it again from it's factory settings...

Kano's?
It's built on an earlier factory image that had that same bug ... no fix until either he releases an updated version with the latest stock fixes incorporated, or we get a new version through the official channel with his fixes incorporated

Rock and a hard place ...
On the bright side, for me, Nicehash has made some changes on their end and Kano's firmware now plays nicely with them ... I think I'm going to do some scripting on my GPU miner to monitor the S2 w/ Kano's firmware and when it resets to stock, put my config back on it and restart cgminer ...