(I tried to find out which is the closest, already open task, but I didn't find the best one. Please mark as duplicate if it is.)
I use VisualEditor since an early beta stage, and I had several problems which mainly solved during this time.
But I would like to report you that the performance and reliability of the surface is still a problem.
- Loading the VisualEditor is very slow for larger pages. Sometimes even for smaller pages. This is very annoying and results an unsatisfied user experience. Sometimes I still use the older editor surface, and there I realized what a big difference if I can edit the page 1-2 seconds after I clicked the edit button instead of waiting 10-20 seconds before.
- The loading progress of VisualEditor sometimes just stuck. The progress bar appears, reaches part of it, then stops. Sometimes few minutes later the page appears for editing, sometime this never happens. Usually reloading the page helps, but sometimes not. See a print screen here: https://pasteboard.co/GKEw56L.png
I am sure, it is not easy to solve these problems, but we should improve, because the bad user experience has an effect on the whole reputation of Wikipedia.