This got out of hand so fast. XD Here are some facts that i gathered in hard work.
**- Unity and Ue4 make alot things as good but in a different way
- Unity is more popular by fact, i think they were one of the first companies ever to introduce a engine that is not only for AAA. (Unsure but you get the idea)
- While Unity is trying to speak to a big group of people at once UE4 is trying to focus on a smaller one. UE4 tries hard to get its quality going and beeing stable, while Unity is trying to get as much people as possible.
- I was told Unitys documentation is larger and you get a lot more tutorials on it.
- Unity is not free as UE4 is, but both come with some license sheets. Like Fee for epicgames.**
Unity is different then UE4, but after all what i read heard and felt my own its not better or bad.
Some go for Unity and make great games and some for UE4.
I a direct conversation you would use one argument the most: EngineXY fits me and my skills very good thats the reason i took it.