With current wikitext editor, I could begin editing the EnWiki article United States within 3 seconds of clicking edit.
With the New Wikitext Editor there was a 30 second delay before I can begin editing United States. That is bad.
Then I tried one of EnWiki's largest articles, List_of_named_minor_planets_(numerical). (Yes, that is a gross article.)
With the current wikitext editor I could begin editing within 5 seconds.
With the New Wikitext Editor my load time was ONE HUNDRED AND TWENTY SEVEN SECONDS. That load time is utterly obscene.
[[ https://en.wikipedia.org/w/index.php?title=Wikipedia%3AVillage_pump_%28proposals%29&type=revision&diff=771419642&oldid=771287413 | On English Wikipedia there is strong community consensus that this issue is serious enough to be a deployment blocker. ]] The key text was:
//Actionable Blocker: Load time. Load time is a priority concern for both new editors and experienced editors. Possible resolutions://
* //We could happily retain our current wikitext editor; or//
* //if possible, drastically reduce New Editor load times, particularly on large pages.//
The obvious ideal would be to match or improve current times, with additional time subtracting from the value of the New Editor as a whole. This priority aspect quickly turns the New Editor into a clear downgrade from the current editor.
Preview times also need to be fast, which is even more critical. The editor only loads once, but 30 seconds to preview easily becomes 2 minutes or even 5 minutes when preview needs to be used multiple times.