Results of the Reddit tests held on January 26th 2016:

-Ambient sounds generally too loud.

-FPS drop at open window [hotel - second level], caused by the combo of the refraction shader on window glass and the animated, translucent curtains.
This glitch has been already noted previously, but fell out of attention because the area is not connected directly to the battle zone.
However our recent Reddit test has been enlightened the real situation: When a player(s?) goes [or staying around the same visleaf - but this is not proven yet] through the window's portal, he makes certain servers lag thus exposing team strategy.
Solution goes either deleting the animated curtain or changing the shader of the window glass.

Thanks everyone for managing and participating on the events!