About engines' crashes

I’m new to game development and … i keep hearing about performance issues and instant crashes while trying to choose a game engine …
(I know that it all !!! has to do with the game i want to make and so on … but i want a comparison and your opinions and not guides )
And I got a question that have to be answered !!
I’m pretty sure that some members here have tried unity 5 or cryengine 5 before or after UE4 … so …
I want to know :

  • which one of these 3 engines has the most unpleasant experience ???
  • and when does the engine usually crash ??? (editing , rendering, exporting, …)
  • and which one of the 3 needs performance optimization the most ???
  • and which needs visual optimization the most between UE4 and cryengine 5 ??? ( since unity simply can’t be compared here “no offense here !!” )
  • some pros and cons are appreciated too ^^

Unity probably crashes less due to the lack of complexity, but you’ll have to buy some stuff from the asset store which will have bugs.
Cryengine is OK if you’re making a game like Crysis, but not so great for other games.