Well basically RGBA blend maps is the technique of texturing , by using red , blue , green , and alpha , and then replacing those by a script or code by a tileable texture(each color represents a texture) , and they don't make seams but blend together.
Cryengine 3 was not good,because it wasn't practical to everytime export the mesh as a .gfc and then reexport the textures as special cryengine material .
I'm looking at unity3D right now as im writing, last time i checked i couldn't import the model , but now i am able to , maybe I'll study more on that.
All those engines you counted , are not pretty good except unity3D, unreal (which is really good and i would use it , but it's lagging for me for no reason >.< ) and ogre(but it requires a lot of programming and doesn't have an editor).