There is lag on everything currently. casting, mounting, etc are bad enough, but item interactions are truly truly outrageous. Each item is queued seperately and each is currently taking longer than a hearthstone to finish. Trying to do a (what was) 2 minute cooking daily now takes at least 20 minutes - even for the ones where you only need to loot 4 carrots or such. On that note, forget doing fishing in Dalaran; audio cues, visual cues, doesn’t make a difference, you’re gonna miss your catch every time. I’m playing on 29ms but the gameplay is worse than what I recall from the days of dialup, its appalling. Sort. It. Out.
edit: Seems that the layering has since been reintroduced, the lag has gone, thanks to whoever amended that. Hopefully no repeats!