Well done, sir.
But, if you look at it from the standpoint of the most popular choice…
Do you have a cite of that being a culinary standard?
Steak done-ness report from Roots Steakhouse, Summit, NJ:
I ordered my 16 oz prime NY strip medium rare. It came out done just a little more than I might have liked, but was still very very good. In the interest of science, I did surreptitiously poke my finger in the center to confirm that it was indeed warm. Next time I have the opportunity to eat prime beef, I’m ordering it rare, though.
But the most popular choice is relative to time, place, and meat. The MR beefsteak has not always been the most popular choice in America.
I agree, but how can I pretentiously order a steak that’s halfway between the pictures medium and medium well? 
Because really, the medium well pictured is too brown, and the medium too pink.
No, I don’t. But I’ve always thought that this “rareness” phenomenon, and dare I say snobbery, in modern cooking is an imported culinary ideal mostly perpetuated by the aristocracy and wide ranging culinary arm of the French (and uncommon Japanese tastes, in more recent years). It is a modern propagated myth and purely a forced matter of preference that Americans prefer rare meat.
After looking at the linked pictures, I think I want a steak halfway between medium rare and medium, too. “What I want is a nice, warm, somewhat firm red center. That should be a medium/medium rare hybrid.” sounds just about right. Maybe I should order it like that in the future. I always just order medium now because anywhere between medium rare and medium-well is fine with me, but this would be my preference for the ultimate steak.
A little geographical bragging - I live in the middle of Alberta beef country. That is some nice beef. 
It isn’t forced, nor is it modern. A lot of people who grew up with overcooked meat think medium rare is some kind of trend when they grow up and move out of the house and are exposed to different tastes.
The rarer the steak, the jucier the steak. That’s all there really is too it. Plus, the texture is softer, and the flavor is beefier.
Med rare is the most often ordered doneness at high-end steakhouses, with medium a close second.
I don’t see the point in saying one opinion is more right than any other. Eat steak cooked the way you like it and let everyone else do the same. I’ve has blue steak and liked it, although I prefer it cooked a little more. If I get a medium rare steak, I’ll eat it and like it although I prefer it cooked a little less.
Sure, but like you say, it requires special treatment and not all places are going to know the special trick. I’ve no doubt that decent not-dry well done steaks are possible, but more likely than not you will get a dry cinder.
Only a rare person says things like that.
I don’t see the point in it either, but I’m going to challenge anyone who says that a popular doneness is “forced” or trendy, or any other number of inaccurate assumptions.
We’re talking about a steakhouse in this situation, not some restaurant with filet mignon on special tonight. I’d say 99.9% of all US steakhouses know how to cook a filet above medium rare.
Regarding your boss’s preference for WD Prime Rib in a banquet setting:
You know those electric insulated heating carts for stacking, transporting, and storing banquet plates at a safe temperature before service?.. Shit! can’t think of the restau-lingo term for them. We had a simple one word description for them…kinda like ‘fridge’?
Anyways, usually the first cuts of prime rib we put into the heating cart we saved for the people who preferred more “well done” temperatures. First in, Last out, got the most well done pieces. If we needed to, we could add a bit of hot jus to a medium piece and get a medium well with some time in the heating cart. Or we just found them a good end piece and gave it the same hot jus treatment to attain a Well piece.
Cambro
FWIW, it was only fairly recently that I learned that there was “over medium.” I thought that over easy was just the name of the style of flipping the eggs over.
I’m a steak snob, and while you can find people that will charge you whatever you want to pay for a steak (especially with silliness like Kobe beef), the best steaks I’ve ever had (Sparks in Manhattan) aren’t too much more than that. Of course, that’s just a steak. Regarding doneness, my understanding is that a given steakhouse will have a standard method of cooking, and they just “shade” up or down based on the customer preference. This varies widely…if you’re at a chain, they tend to be liability-oriented, and hence they tend towards “more done”, whereas non-chain steakhouses tend to be fiercely against the higher degrees of doneness.
You want to talk serious? A few years back I’m with my boss at our client, a law firm in Dallas, TX. We speant the better part of the afternoon with the client (at a rate of anywhere between $200-$400 an hour) studying one of those butcher charts before going out for steak dinner at III Forks.
Labrador Deceiver is correct it can be done. Restaurants will avoid that option however. It simply takes too long. If its a single dinner they might do it but a member of a party its going to make everyone else have to wait in order to send all the meals out at the same time. My experience at Mortons a few times with a friend who orders fillets well done is they inform him they will have to butterfly(slit it in half like) the steak in order to prepare it well done which he is ok with.
I’ve eaten at a number of top steak houses, I’ve never known them to offer specific categories like ‘med rare plus’. If you want to invent your own category you can, simply explain exactly how you want your steak cooked and they will do so.
I think it is just the opposite, people who grow up with no “culinary home or touchstone” assimilate foreign customs easily, and non-traditionally…