NCM on E-Marr tried this on Fri for a couple of runs. Heaps of lag throughout the event. Phase 2 adds didn't spawn properly. Our 2nd attempt we got 6 compellers, the first attempt was 4 enthrallers and 2 compellers. Our 2nd run we got a new instance and it was just as bad if not worse. It was a lot more difficult to move the adds also. (they do normally warp a bit, but i find if you go around the flower pot slowly then they are fine - but not this run ).
Havn't done it in a month or so, but I don't remember it being especially laggy (or tower of rot being laggy since the fix months ago either). Humm, posted this before the post above. I bet we'll be trying it again soon in open raids, we'll see. But last time about a month ago there was no problem at all.
We have experienced this issue on Tunare for the last 2-3 weeks with the open raiding force, AH. The lag is pretty horrible for everyone inside, most of us were on vent complaining. We managed to beat the event in spite of the lag in our last run, but we had to abort after several attempts of severe lag / wipes in previous runs. Maybe since the last patch?
Aye happend to CoN last week. We got down to the end had 15 people lag out completely and a number of people didnt know the guy was dead (consoles still showed him at 75)
When we ran into lag during this event, it seemed to be directly tied to how many mobs were up. In the instance before the event started, there wasn't any noticeable lag. When the event started, the first boss and adds spawned, then lag hit immediately. Delay was bad enough that the adds refused to leave their spawn-point unless pulled with a forced movement effect. Fellow raiders were saying anywhere between 5 and 20 seconds between hitting a button and the action taking place. As we killed adds, the delay was improving, until we had only the boss remaining and almost no lag at all. Once the first boss was down, the second boss and adds spawned, then lag was back just as bad as ever.
We have also see the horrible lag on this the past 3 weeks. We believe it can be atributed to not only mobs but also some of the Marketplace auras and Nimbus's. The arachnid one actually locked up the zone on us once, or that is what we suspect. Otherwise it seems lagged but playable.