The difference between CryEngine and UE is that UE takes more time fine tuning their tech so it runs better.
CryEngine is very unoptimized compared to UE and UE4 can pull off the same visual quality as CryEngine with better performance so i don’t mind waiting for real-time GI which should probably be implemented in full within the next 2-3 months.
The CryEngine guys just like to be first-to-market with something rather than optimizing it and releasing more stable versions of it.