So our Raidgroup also has this problem...
I find it funny when Bioware says "Its on your end" when EVERYONE in the raid has the SAME issue at the EXACT SAME TIME!
Bioware, yes... it is our connection ;-)
The funny thing is we had this lagspikes also on our old server which had not as much players as our new one.
But yes, it did get worse with more player.
Has BW officially said it was on our end? I haven't seen anything, and I sincerely doubt they would be so shortsighted to think that.