I started off with Eclipse in school, I still stash all of my code in a folder called 'workspace' as a result.
But, I've since switched to intellij for Java (and later, lightweight editors like Sublime Text for JS, until a while later JS finally got modules and editors added more support for JS), and nowadays I'm using it for everything; I'm currently managing a 200KLOC application (it's too much but my employer isn't hiring, sigh) in at least four languages (JS, PHP, TS and Go, it's an older application and a rebuild I'm working on), and intellij has no qualms with it whatsoever.
I even set it to PHP 5.2 mode so it warns me when I try to use `[]` to initialize an array.
Oh wow, Eclipse.. That reminds me, I was using Netbeans eons ago (2010 more precisely xD). For this reason, I'm using the Netbeans key mappings in all my editors. I kinda feel bad for those editors, and I hope they still have an active user base, but oh well, it's survival of the fittest I guess.
I still use it. I always hear these raving praises for IntelliJ so I guess I have to force myself to move to IntelliJ. I tried a couple of times, but always fell back to Eclipse due to familiarity.
What do you think is the biggest difference between the two?
I suggest giving IntelliJ a shot but, honestly, if you prefer Eclipse then stick with it. I originally switched because at the time IntelliJ had better code navigation, better version control support, better static analysis support, and an overall much better aesthetic IMO (especially in dark mode). Things might have improved in Eclipse since then, but I haven't tried it in a long time. I think the last Eclipse version I used was Juno.
I do a lot more Python work than Java nowadays so I use PyCharm much more than IntelliJ, though they share a lot in common. Aside from those, the only IDE I really ever use is GNAT Studio for work. I suppose I used Android Studio for a while, but that's basically just IntelliJ with some Android-specific features bolted on.
I was forced to use Eclipse for a while ~2010, never liked it.
It's funny to look at how many editors one comes across over the years. My first one was Borland C++ as a kid. Then came a mix of Visual C++ and Bloodshed Dev C++ during high school. During university I tried a bunch of things but mainly nano, gedit, Visual Studio, and Eclipse. In my early career (2013) I finally got into Vim and haven't looked back since.
I did try out Rider a little over a year ago. It was really good and I'm impressed with some of its features. But it wasn't enough to make me switch.