Hi,
Unity is the only game engine I can use so I can't compare with the other ones. I would say though that it's a great game engine with almost unlimited possibilities if you take time to learn how to use it. That is probably true for all game engines, however the community behind Unity is extremely active (forums, Q&A, youtube tutorials etc.) so usually you can find a answers or explanation regarding whatever you have in mind.
I think you should definitely give it a try! For Android and iOS it is very convenient as you don't need to worry about that will you develop (unless you integrate IAP or other Google/Apple related services, but even then there are plugins which can help you).