I've just started trying this. First the question: is there any way to preview edits?
The issues: it is very slow to load, up to 15 seconds. Second, I needed to look at the deleted edits of a red link, but the wikitext editor opened as soon as I clicked on the red link, which meant the deleted edits were no longer a clickable link.
Update: I've just found how to preview. There's no indication that first you have to click on save.
An external link in the post didn't show up properly in preview.
When previewing a new short ref, one using sfn, it wouldn't let me click through to the long ref, so I couldn't check that the templates had worked. When I clicked on any short ref in preview, it opened the current version of the article in another window, which doesn't help if the reference hasn't been saved.