I think there is no easy answer to this. The reason is that there are a lot of "buts" and "ands"...

In general both have nice WYSIWYG editors where you pretty much can just hit "Play" at any time and e.g. see your particle effects running and things like that so there in general there's no slow build process like it's the case for 3DGS...

If you want to talk about maximum control & performance it's all about the language. Unity uses C# while UE4 uses C++. You also have full source access in UE4 which can be an extremely powerful feature (I think Unity also grants C++ source access nowadays but at a price). So if you really want to not only write very efficient code but also want to have in depth access to the engine itself UE4 is outright fantastic. We're talking about C++ here though so it's not always as easy as C#. I had to dive into some C++ code written as templates in a totally different kind of software and I hated it...
So while C++ in general is very nice it's up to you what suits you best. You seem to be an IT professional so you already might be very skilled in C++. Then this might be a big plus for UE4. For most users I'd say though that C# is easier to handle while you of course sacrifice some power, performance and possibilities. In my opinion that won't be a problem though unless you try to squeeze the very last bit out of your software to e.g. get to the needed framerate for your console game. So unless you feel perfectly at home in C++ Unity should be the choice for more easy learning...

Don't make up your mind right now though as here comes one of those big "buts"...

UE4 delivers blueprints out of the box. If you don't know what this means have a look at this:
https://www.youtube.com/watch?v=7Mzz6Ihivc8

It's a built-in visual scripting solution which enables you to easily and quickly create logics for your game like doors, elevators, animations for your characters or even rather complex AIs. This way you don't need to touch any C++ code at all but can click your functionalities together (and test them) right in the editor. I think for the type of game you're planning to do this would be perfectly sufficient. The only real downside of using blueprints is that those things don't nearly run as fast as code written in C++ or C# would. Its performance isn't total crap either though and for e.g. a horror game where you don't have very complex tasks running all the time (in contrast to e.g. a real time strategy game like C&C or Starcraft where you wouldn't want to do the pathfinding algorithms for the hundreds of units via blueprints) they provide you with the needed functionalities while being created in very little time and without extensive learning of the engine's API and stuff like that. This really is a huge advantage of UE4 - you can buy similar things in the Unity marketplace as 3rd party tools but to my knowledge the UE4 integration is far better and gets constantly improved as it's a general engine feature...

This of course doesn't make one's choice easier...