Selecting an engine is probably going to be the single biggest decision you will make as you will be getting into bed with a third party interest so take the time to read the small print, and yes I do mean you Apple guys. 
The deal breaker for us is Cry is being sold as a subscription based service just like you would pay for your Internet connection. Don’t continue the subscription just like your Internet connection you will be cut off from using the engine and tools until you sub up again.