Trying to link to Barack Obama page. Brackets manually added in wikitext editor here do not create links (at least within preview). And this Flow wikitext editor is reformatting my text after every preview. The brackets disappear along with the text within the brackets. Text laddering is introduced at that point. After I click the preview link within the wikitext editor, it goes back to Flow's Visual Editor. When I try to create a link within Flow's visual editor I can't get rid of the popup window.
Mediawiki software is being hurt by Flow driving away people from reporting and commenting on Mediawiki bugs and features.
See en:Barack Obama (can't create a link). I just timed VE loading for me using Firefox. Took 30 seconds for the blue loading bar to disappear. I watched the clock count off the seconds on my PC. So I wasn't guessing on the time.
You are asking a new editor to choose a default editor. Then after choosing VE they try to load it on a page like the Barack Obama page. Then this new editor is supposed to now know how to choose between the 2 edit buttons that now show up. And they only show up at the top of the page. They may not be at the top of the page.
Layers and layers of confusion for new editors. It is well known that any delay in page loading causes people to move on. At least it is true on the web in general. Many studies show this. So why would it be different on Wikipedia?
I say the lesser of evils is to show the 2 edit buttons from the beginning. It is likely newly-registered editors started as anonymous IP editors at first. So they know that the wikitext editor is fast. So they will naturally search for it if they get stuck waiting on VE to load. But not from within VE. Not as newly-registered editors.
They are more likely to X-out the page, and come back later, and choose the other edit button among the 2 edit buttons that show up on every section. Cause they know that one of them has to be the fast wikitext editor they know from IP editing.
Once they get experienced they can choose a single edit tab from preferences if that is what they want. Many experienced editors will not do that. They will keep both edit buttons. Because even I find VE useful for some purposes. Editing tables in my sandboxes for example. VE is good for removing unwanted columns. Or for adding blank columns and rows.