The Jetbrains suite of IDE's. Particularly Jetbrains Rider. The platform ~~they are all ~~ many of them are built on is open source though, and you can get free licenses for all of their products if you are using them to develop open source software!
Reasons are usually just newest kernel/mesa/etc. Most of the time the difference is very small, and often inconsequential. However, every now and again there is a major development that might make it worth it (IE: The graphics pipeline that all but made dxvk-async obsolete)