It's the definitive version. Great port and Capcpom did the community right by it.
First time in 60fps, most of the effects that are present in the GC version are also present here, like specular highlights, and there's currently a modder (crisdecuba) making a
FANTASTIC texture mod for the game that really looks incredible.
Another modder is helping him (Albert) who lives in Spain and is finding the ACTUAL original, source buildings that Capcom used when designing RE4.
So you get stuff like this, which is a texture created from the actual original windows that Capcom used for textures, and the following one, which was a picture of the actual hole in the wall in Spain that Capcom used in game to texture.