I blame it on excessive number of stats items being tracked by the server. If you think about it the more stats tracking they add to games the worse they seem to get. The old games never tracked much if anything and they ran much smoother.
I'm wondering what the QA guys were up to during testing of this patch.
http://www.youtube.com/watch?v=fNsr7Edq7e4
http://battlelog.battlefield.com/bf4/forum/threadview/2979150493816594684/
http://battlelog.battlefield.com/bf4/forum/threadview/2979150493816845808/
http://battlelog.battlefield.com/bf4/en/forum/threadview/2955064773357917195/
http://battlelog.battlefield.com/bf4/forum/threadview/2955065224207238087/
In other news R21 server files contain Second Assault maps (XP0_Caspian, XP0_Firestorm, XP0_Metro, XP0_Oman).