A question on perceived lagginess of the player's actions. We know it is the case that as you're running around, if the server sends you back a packet saying "no, actually you're here", you get adjusted to be there. This is usually termed 'rubber-banding' since it feels like there is some force pulling you this way and that. Understandable, necessary, etc.
My question is that sometimes I feel like the direction that I'm looking is also subject to this. Is this the case? If so, might I suggest removing this? I think it could go a long way towards decreasing the 'mouse lag' feeling players have. If the server is getting bogged down to 15 or 10 ticks, then as you're trying to swing your view around, your local client is sending packets to the server saying 'facing this way, now that way' and meanwhile your system is rendering you facing this then that way, but then when the server finally processes your first packet, and sends you back confirmation saying "ok, you're facing this way" your view gets jerked back.
My feeling this is the case was when during a game I hit 'connection problems', and all of a sudden my mouse lag was gone! The server was no longer talking to me, so my client just kept on rendering me facing whereever I wanted and the server wasn't contradicting it.
Counting bodies like sheep
To the rythm of the war drums