@loeix
The same here!
I see only real advantage of Editor-X in it’s RESPONSIVENESS!
In all other aspects the points goes to → Standard-Editor.
And i also do not understand why wix is generating 2-different editors (still both buggy) instead of rolling-out a perfect combination of both.
Like AyDontLoss already described, working with Editor-X is very tiring/exhausting and even more time-consuming as the working with the STANDARD one.
Adjusting / pinning / docking and do some setup for almost every single element → this is surely not the best solution!
It would be better to give the standard-editor the possibility to make your site some kind responsive, too and the Editor-X can go to → garbadge. 
I am forced to work on Editor-X and just crash my head against the wal, because there is NO MULTI-STATE-BOX in there. How can this be? How to generate complex menues without the missing element?
Or it was just rolled-out to early, without 100%-functionality. For me → still BETA-VERSION !
Sorry if i am too direct, but feedback is feedback 
no matter if it is POSITIVE or NEGATIVE. 