i don't know what is the current status of maintenance project, but so far i noticed these few things after it started:
- login popup window in the main menu works faster;
- server filters seem to work better (maybe placebo, who knows);
- third (and the main thing) - playing the game actually seems worse, in terms of increased server lag and occasional fps drops on every single server and game mod i tried since updating process began;
since i don't know at which stage update process is up to this day, i hope server lags and fps drops will be fixed, since i didn't have any of those before maintenance started.