I've seen Edberg mentioned a lot as the best "technical" volleyer, as where McEnroe is often cited as having the best touch and is more of a magician.
But, doesn't this take something away from each of them? Edberg looked more mechanical than Mac, so we assume less feel, less touch, but he had that in spades.
And, from a technical standpoint, I don't know why McEnroe isn't as technically sound as Edberg, maybe it's the look of his strokes. All I know is that the key to great volleying is compact strokes and keeping the racquet out in front. From a technical perspective, Mac had these qualities as much as anyone.
You are right in that Edberg had magnificent touch and feel for the ball. It ONLY suffers in comparison to Mcenroe. Edberg was right up there, but Mcenroe also got that reputation, because of the creativity of his touch shots. At his best, he seemed to be "creating". Ad libbing various shots and volleys, exploring angles, paces and spins. That too, required the surreal touch.
In terms of technical development, yes, Mcenroe's quirky style made him seem less sound than he actually was. He certainly was as strong as Edberg in many technical departments, but in some, eg. footwork and getting down low, he was not nearly as good or as consistent as Edberg. Again, he simply used his hands to compensate. Edberg, had magnificent touch, but he still used his legs and body in about as close to text-book perfection as anybody could against the opposition he faced.
These 2 are the best I have ever seen. Rafter is not in the picture, I"m afraid.... and that's no insult to him. In fact, he might even have been as effective, or nearly as effective up there as Edberg or Mac...so in that sense, I'm almost deducting style points, for touch, variety, grace, and sheer talent.