I'm so f**king tierd of this shit lag! WE CAN'T EVEN DOWN THADDIUS!!
Last night, it lagged so bad, that out OT on Patchwerk got hit 5 times before we was able to heal! Guess what? He died, due to the cause that around 80k damage hitted him before anyone could response!!
God! It's so freaking annoying, this isn't hard, it's impossible! Give ous harder 10man! FU BLIZZ!!
I would suggest that you either stay to the 10 mans or play 25 man during late night/early day.
I think the problem is that there's so many people that get achievements and statistics in 25man and it simply lags down, too much data transfer.
I believe the instance servers are shared by battle groups (BG/5/10/25/40 having one server each or more).
Not sure thou.