Freezing, getting hit without seeing a swing animation, rubber banding (where you walk forward then return to where you started from) and got disconnected from strat battles and EU 1 a few times. Made blocking really hard.
Played this afternoon after finding an entry on a forum about window defender being activated by updates then causing lags and seemed much smoother on EU1 once I turned off its real time scanning function.
May be coincidence, may not work for others but I was finding the lags were affecting my enjoyment.