From the patch notes:
"Implemented a fix that will marginally reduce the server lag while in Cyrodiil"
They are working on it Kaytlin - I just don't think that they are aware of the "what" that is actually causing it since it occurred after a patch they did - so they are backtracking in steps to attempt a fix. It is either this way or to completely undue a patch which is not a great way to do it.
I think that is why they always say "will "reduce server lag" instead of "eliminate" - they will find it. I'm still getting over 30 FPS most of the time and only have to re-log generally 1 time every couple of hours. This also plagued GW2 for quite a while - we all remember the invisible enemies we used to fight and there were far fewer of them on the screen than there is in ESO. I realize no one likes it - but baby steps is always the better way. There is seldom an instant fix.
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I also agree on the Vet content. It was extremely hard - and leveling was at a snails pace - well, a snail with a bad hip and a broken foot. I don't think what they have done will speed it up that much. But as an example - doing the starter island in the other zones as a V1 is a challenge - a pretty good challenge. Which I didn't expect. I would think the challenge should be comparable to when you first start - and it isn't - it is much, much more difficult. Yes, I could handle it - but it isn't the same and for the amount of Exp you get - the risk reward isn't there. I will fight through it regardless of how they handle it. I think reaching V12 should be a "great" thing and when I reach it in a few years (cough/cough) (wait - I think I'm serious) it will feel like the accomplishment it should be.