Filter works fine for me.
Unity on Windows is unplayable from the testing I've done, unless I'm missing a special installation or configuration setup that improves performance dramatically.
Since you are a member, download the standalone. See Fizzer's post here https://www.warzone.com/Forum/249786-warlight-unity-alpha-now-available
The browser expirience seems to vary a bit from player to player. So I would just try diffrent things and see what works best.