I am working for a software editor and we mainly use Java as backend language. I use to work with Eclipse since around 2010, only for Java projects. Here is my journey and a quick comparison of the tools.
First of all I need to inform that I am actually Product Owner and not anymore a full-time developer. So I am still looking at Java source code project, but with a different level of usage than before.
VSCode is relying a lot on extension. Each extension add a little extra power to the tool. So the initial text editor can be compared with a fully featured IDE once the right extensions have been installed.
I don't want to present each extension, I found this article which is describing that very well.
Globally you can relly on the Java Extension Pack that install all the main Java extensions for you.
This is I think the most important change between Eclipse and VSCode.
Eclipse is relying on a workspace concept where you import Java projects. My main concern with this approch is around multi-modules Maven projects : once you add or remove a module, Eclipse is lost and you need to import again the missing module.
VSCode is more like other editor (Atom...), and you can simply open a folder that contain your multi-modules Maven project. If some project have been removed then you will not see it anymore.
Folder presentation in VSCode
Workspace in Eclipse
It's not a big difference but for me it is more easy to switch between projects. I do not loose anymore time to import projects, I just open the right folder. There is also a workspace system in VSCode to open multiple folder at once, it may be useful if you work on multiple projects at the same time (front and back for example).
The global experience is very good.
You still have auto-completion and JavaDoc is shown when it's necessary. There is also an equivalent of the Run Configuration with the Run panel to fire your project.
The Run panel rely on a
launch.json file, and it can be saved on your git repository if you want to share it with team-workers.
The right extension help to run tests. There is also some helpers to run the test directly before the test method or the test class.
Git is directly available in VSCode. I have never rely on any Git addon in Eclipse, as I found some products buggy. So I was relying only on the Git command line. I still rely a lot on the command line but I am happy to see this very good integration of Git directly into the product.
And you have some indicator directly in the editor (green if new line, red if removed lines...). I have never see this kind of indication inside Eclipse. Probably I have never installed the right extension ;)
There is also a Maven extension that let you execute all Maven commands. But here I prefer using the excellent terminal that let you do what you want. It's here, just use it.
One month after VSCode installation and first test on Java projects, I realize that I haven't opened anymore Eclipse. Just today to make a screenshot...
I have not yet speak of the performance too. I have a decent MBP and Eclipse take always a couple of seconds to startup. VSCode start in less than a second.
So just an advice: get a try on one of your Java project, you may be surprised to change your habits !