Here are my views on it:
Cryengine 2 is better than Cryengine 3 in only these ways:
1.Textures
I think Crytek tried a bit harder to make good, realistic looking textures in Cryengine 2 than in Cryengine 3
2.Fire and smoke effects/explosions
I think the fire/explosions in Cryengine 2 looked a bit more believable, I still like the fire/explosions in Cryengine 3 though. The smoke and effects looked better in Cryengine 2 and thats a fact.
3.Volmetric Clouds
4.Vegetation
Cryengine 3 did better in everything else
Again, I don't know if people are over this, but I just wanted to share my thoughts