I'm also an Evernote escapee. I basically refuse to learn Markdown, as my head is already full of all sorts of markup languages from MediaWiki and its templating language all the way back to ancient SeText (from which Markdown borrowed a few things). Just don't have the patience for it. I use the WYSIWYG editor. Did install a boatload of plug-ins though, to get additional features.
I use the Windows desktop application version of Joplin (for now; will probably soon also install it on my Mac and so on, and set up the synching).
There are some quirks to Joplin, like copy-pasting items from one part of a list to another rarely works properly, and needs manual repair, sometimes of more than one kind. (Maybe it works fine if you are in Markdown mode; I dunno.)
Something I've noticed is that when you add a new URL to a note, it is "inert". You have to leave the note and come back to it for it to get colorized and become Ctrl/Cmd-clickable.
I did work out that the annoying double-height spacing after a line break can be avoided by doing Shift-Enter/Return instead of just Enter/Return. (Though how well that works depends on whether the note is "native" to Joplin or was imported with pre-existing formatting; that's probably resolvable by getting into the source view of the note and removing some extraneous styling code.)
The web-clipper feature isn't something I use, so I have no tips regarding it.
The main frustration for me is the lack of text coloring and highlighting. This just needs to be built into the editing tools, and to be "agnostic" as to what editing interface you are using. I do have a text-coloring plug-in, but it's not very good, and doesn't closely approximate the colors I was already using. It also doesn't work in an HTML-imported note. One of my notes (a ledger) makes extensive use of color, and was not very useful to me imported as a regular plain text-and-Markdown note, so I HTML-imported that one. But it's very difficult to work with, since there's no interface for "fancy" HTML elements, and the colorizer plugin doesn't work on HTML notes. The only way I can make use of color in the document for new text is to very carefully copy-paste already colored text, including some whitespace of both sides of it, and then edit the pasted version, but even this sometimes doesn't work the first time. (Well, that or get into the HTML editor and work with raw HTML and inline CSS, but that's even more of a hassle.)
Anyway, the more I get used to Joplin, the fewer complaints I have about it. The first two weeks, I really wasn't sure I was going to keep using it. I think at this point I will stick with it, because the other options I tried so far were inferior.
PS: It's also annoying that the "Code Block" editing toolbar option won't work with a pre-existing text selection; you have to cut the desired text into the clipboard then paste it into the code block dialog. But I'm not sure that's even a root part of Joplin rather than something a plug-in provides.