This had been reported many times, nonetheless do I want to report it anyway: Today we had to stop our T6 raid after 1 hour of lagfeast, and three other german raids I know of canceled their raids after 1 painfull hour, too.
For 50% of our raid it was just unplayable, porting and lagging, fps peaking every 10 seconds.
Rumor has it that only players from germany and belgium had this heavy lags - I can not verify this of course.
Anyway - do something. There are only a few healthy raidforces left, spring incoming isn't helping.