I think a lot depends on how you use Scrivener. In my case, I don’t use a lot of the advanced features. I do an outline with the Outliner before I start. I depend heavily on Label colors for POV in my romances. I use Status indicators but could do without them. Find and Replace, yes. Targets, yes, but I could do without them, only really need to be able to see word count for scenes and whole project. I use Research and Character folders, but not so heavily as others, no images or websites, just bits and pieces copied or typed there. I move, add, and delete scenes and chapters a lot.
I did go through the Tutorial when I loaded 3.0 (on my Mac - I have both Windows and Mac), but only skimmed a lot of things I know I’ll never do. Will investigate that linguistics thing eventually. With 13 and 15" laptop screens, extra windows floating around aren’t a plus. I did rely on Project Notes heavily and had to figure out how to use Bookmarks in a way that they didn’t take screen space I wasn’t willing to yield.
I’ve done a quick Compile to get a draft into mobi for beta readers, and when something is as done as I can make it, I Compile to rtf, bring it to WordPerfect, spell check, proofread and do final picky revisions there. I use a different program for final formatting.
So I struggled with the Project Notes to Bookmarks change (and like it now that it’s conquered), Used Compile to rtf to get a project out of 3.0 on the Mac to be sure I could before I began to work in it, and that’s been about it for me.
The reason I have a Mac at all is I kept hearing how the Mac version of Scriv was so superior, and I wanted Vellum, which only runs on a Mac. So I figured I could use both programs and that would justify the purchase of an older MacBook Pro. However, what I found was I overwhelmingly preferred the Windows environment and didn’t need those superior features, and fled right back to the Windows version.
Right now I am working on a novella with 3.0.1 on the Mac because I wanted to see the differences and get Preferences worked out (the new “flat” look had to go, so I changed a lot of fonts), changed Toolbar to my way, and spent more time than I should have on background colors. I’m not willing to trust my work to a beta of the Windows program, but have also changed a lot of the settings there to to get what I like and experimented with it a little.
I think the answer to your question really is “it depends,” and I hope you’re wrong about the Windows version being as much as 9 months away.