@CruciasNZ:

I don't think that's remotely relevant. I've had the exact opposite experience with FFXIV - where this game performs far better than what I'm used to. I think there are network issues, but not driven primarily by the position check. As long as the connection remains stable, human reaction time is more than 100ms - you aren't going to see much difference at 200ms checks. Either way, there are way too many variables to simply claim that you can do X/Y/Z there, but not here.

@Jinko:

No, I don't. Developers compromise far too much. If people wanted a 200ms position check, I'd make all enemy casts 100ms faster. If you had issues under the 300ms scenario, you should still experience the same issues on 200ms.

If you are lagging, then you are both moving slower and noticing casts too late. It goes both ways. Not everything is simply on the back-end for positioning. You can't possibly react to what you can't see, which has to be considered when talking about lag.