Really it does depend on what the final outcome is.....
The skin type of a person also plays a big part, the pore size....etc., and as already outlined make up and lighting.
In you pics Ciaran, I personally like No 2 because, all but for a wee bit more healing, it holds the detail and reality of the image as a portrait.....the next two, retouching is more obvious to me but then I am looking from a perspective of one who retouches....
Depending on what I am doing Ciaran, if its a client portrait to hang, I have seen myself working for literally hours....using healing, gaussian and clone........if I am doing graphics then the process is completely different....its extreme retouching, less time and to the point of surreal, to achieve the 'unreal' reality of what the brief dictates.
But I know one thing.......good retouching is very time consuming...
Going off subject ....I have never had a complaint from removing a spot
..but ironically, I was asked for an image of a spotted person (if that politically correct) last year...and I could not find one!! Its hard to put spot/ blemishes onto a face!!
Art