3.0 doesn't really change the interface. But there's a good third party overhaul called PhotoGIMP that changes it quite a bit and makes it pretty nice to use.

There's also a plugin called Resynthesizer that adds in the ability to do content aware fill, and the G'mic plugin, which adds hundreds of interesting effects and tools (works with many applications, such as GIMP, Krita, AffinityPhoto, Paint.net, etc)