It all depends on your skillset... not just with code but with design, art, and also how good you are at learning the prescribed tools. I am not a fan of Unity, I think it's vastly over rated and in our corner of the market (hobbyist, solo developer, very small teams) the Unity projects are no more impressive than what is produced by TGC products. If there's an impressive solo project in Unity or Unreal, then it tends to be because the person is a 3D artist, or has spent a chunk of money on media. It's better to pick the engine that supports what you yourself can do, not what you might be able to do in 5 years.
I have one main project in AppGameKit, currently working on a very special terrain system that gives 5 detail textures with normal map, ambient occlusion, height map (texture stepping for fake offset shading), roughness and specular... it also has a bitmap normal map for smoother shading, and a tile map for smaller details. Squeezing all that into a GLES shader is not straightforward but a good challenge, and it will look amazing. Sometimes its more fun to take a limited system, like having only 8 textures to play with, and making that work for you, than just using Unity or Unreals built in tools to make the amazing happen. There's a bit of reassurance when your dealing with actual code, if something doesn't work then its your fault, and you can go fix it. I used to dabble in Cryengine, then they started disabling features that were a bit buggy, and I can't work like that - I'd rather take the long way round and be responsible for everything... but game development should be fun, so I don't go to the lengths of using C++ all the time unless I have to.
I started learning Unreal again, but mainly because I want to make VR games since getting an rift. Epic's 5% royalty deal seems to be very fair, better than what is on offer with Unity. It is odd, how Unity seems to be marketed at hobbyists and small teams yet the costs are prohibitive - while the more professional option has a royalty system than nobody can really argue with or complain about.
The code is dark and full of errors