>>717317102 (OP)
If we're talking about CryEngine2 the big issue and why it never took off like Unreal3 was it sucked at dealing with Multicore processors. CryEngine2 came out at a time where the future for CPUs was unclear, were we going to advance to hyperfast single core CPUs with insanely high 12ghz clockspeeds, or were we going to do this whole dual-core thing. CryEngine made the bet that we'd be doing single core at high clockspeeds, while Unreal built around multicore.
Multicore won. Unreal3 took off and everyone used it, especially on console and that lead never went away. So the CryEngine, despite getting better later, never made up the difference.