Both of the above are simpler to manage/setup/navigate/run than the F4/8 and SD's, which provide more capabilities which require more complex menu navigation.
I can't speak to the Sound Devices recorders, but I've found the F4 and F8 menus to be easy to navigate and pretty intuitive. I've never used the R44 or DR680, though, so I certainly can't say that the F4/F8 menus are comparable to the R44/DR680 menus. In my experience, though, the F4/F8 menus have been easy to use.
I can speak as someone who used to use (and still owns) a Sound Devices 552 recorder and a Tascam DR680 recorder.
Upgrading from them to a Zoom F4 was a massive leap forward in my life. Zero regrets. Absolutely is a better experience and a better result.
Since the F4 I have then gone and pre-ordered a Zoom F8n which I've been using since day one it came out. (even though I could have afforded the likes of a Sound Devices 633, I just didn't see the value in it there for me even as as a professional who works purely at sound recording. Am happy to wait and see if I see a secondhand 633 for US$2K? That might happen. Or if a 633 mk2 comes out in the next couple of years)