Matt Robinson is the "real" Gordon; the other Gordons are "pretenders to the 'hood"
Of course, when I say this, I am being completely subjective, but Matt Robinson (who portrayed the original Gordon) was always the "real" Gordon for me. But that's because I was born in 1967, so I was right at that "target age" when "Sesame Street" first started, so what you saw in those early "Unpaved" episodes represented the "Sesame Street" that I knew. I probably watched it until I was 7 or 8, so probably any episodes which *did not* have the "episode number" superimposed on the screen while the theme song was playing were ones I was planted in front of the tube watching when they first aired.
And in those early days, Gordon was pretty much the "host" of the show...not really, because the main cast were all pretty much equal, but he was the closest thing to a central host. And yeah, Matt Robinson played Gordon with a more "urban" attitude, but like I said, that's the Gordon my friends and I all knew and loved.
So when he left and then the two other Gordons came in, you bet I knew the difference. Something just didn't seem right. "Sesame Street" was still a great show, and still had great performers, still had great Muppet characters and all the rest of the things that made it great, but with apologies to Big Bird when he was mourning the loss of Mr. Hooper, "it wouldn't be the same."
I don't mean to "dis" Hal Miller. And I don't remember a whole lot about either Hal Miller or Roscoe Orman (at least from my childhood), but I do remember a scene with Sam The Machine, which I am pretty sure involved Hal Miller as Gordon, though it's possible it might have either involved Bob or Luis. There was only one skit with Sam The Machine shown on "Sesame Street Unpaved," and it was Sam's (and Hal's) first appearance. I'm sorry that this character has to be represented solely by such a lame skit. Though I liked the idea of Gordon having to smack him to calm him down (of course, that got censored by the political correctness nazis). Anyway, I do remember a skit where Sam had a built-in camera. Gordon (or Bob or Luis or maybe even David, but I'm pretty sure it was Gordon) posed for the picture, then Sam spit out a bunch of shots...but instead of a full portrait, they were all very tight individual shots, one of his nose, one of his ear, etc. That's what Sam would do. He'd show up and announce that he had the ability to do some great thing and try to get everyone excited (though after a while, everyone pretty much got to know how his demonstrations always turned out), sort of like "Clyde Crashcup" from "The Alvin Show." It's too bad the only example of Sam The Machine that's been available is that stupid "Mulberry Street" one. That was pretty lame, and Sam had a lot of better ones. Also, before anyone asks, I do not have the photography skit on tape, I just remember it from over 30 years ago. Actually, that is just about the only specific individual bit with Sam that I can remember. (It does seem like Sam was on the show for longer than it would appear from "Unpaved," because I have seen a cast photo which includes both Sam The Machine and Roscoe Orman as Gordon, so Sam had to be there at least three seasons, if not more.)
And yeah, I remember when Gordon was replaced *again.* And I knew the difference then too. But I agree that other than being bald and for lack of a better term, having less "soul," Roscoe Orman could be mistaken for a slightly older version of Matt Robinson, if you were a really little kid. He has, as Orman said in the "Unpaved" book, "that 'Gordon thing' that people like."