It's been quite a while now that European players experience severe lag-spikes.
This issue made me stop playing White mage at level 44,
and starting anew as a black mage.

Now I'm BLM level 50, and the problem has got worst.
The content is still very interesting, but it's so frustrating to play with these lags,
it's ruining the fun.

Furthermore the "community" after level 50 is not cool at all.
When you get into a dungeon, people look at your gear and if you're not well equipped (to their eyes), they disband, or worst ask you to leave.
They forget everybody (including them) have gone through the same situation before.
These people are also less tolerant (maybe because the game forces them to do the same dungeons again and again)....

It would be good to think about a way to rank officially your progress after reaching level 50, and selecting players accordingly with duty finder.