Hi and welcome to the community.
I work with both unreal and unity and the compilation performance between the 2 are pretty similar and sometimes faster in unreal. Yes, you do have to initiate the build but it takes 2 seconds to build changes. I find unity switching from code editor can take 5 to 10 seconds sometimes.
Setup. It is a little involved and yes unity is fairly simple in comparison. Basically the installer doesn’t add in the net runtime and you need to install studio separately. Saying that, they always just worked for me. I normally use rider however (also for unity) and never encountered issues with intellisense. I used to use visual studio and only had issues when reshsrper is installed so switched to rider as a result.
Work flow.
The biggest gain for me witn Unreal over Unity is many features are done with consistency. Most things work in a similar way so it is easier to move from area to area.
I feel the process of working through projects is not so different between them. You build up your prefabs/blueprints but the main difference is you can create a class that builds up all these components and you can then create different blueprints based off the. This is the biggest difference between them and it does take a bit getting used to.
Overall, given the choice I usually alway will go with Unreal. I don’t even use C++ that much, only when I need to honestly.
The most annoying thing about unreal is when creating classes, sometimes you have to exit the editor and build from the code editor. I have found myself running projects from poweshell from command line while just working in rider. This is a really nice way of working with the code and not worrying about the unreal editor.
Anyway, not sure if this helps or answers your question. Feel free to ask more questions and we can try answer as best as we can.