ES does seem more stable.
Ping have fluctuated quite a lot, but I haven't been running mtr, so can't say if the periods I have noticed it, if it was from my end or not.
(How do you force to show hp/mana over the bubbles?)
There have been minor quirks, but it is stuff I have forgotten about, so nothing big.
There was however one strange thing when I first added forged +cold skill jewels to my gear.
After I equiped the item my hp went to 1, as if I was using the merc only stuff.
I did fiddle around with it, and sometimes I got full hp, but the moment I did teleport it went to 1 again.
It went away after I unsocketed and unforged and resocketed and reforged the gear two times,
and I have not seen it since.
I wasn't even able to reproduce it afterwards either.
Minimum like level 10 would be neat.
I own quite a few mules, but am sad that I can only log in 8 clients at ones