I’ve been to Greece but didn’t eat, or see, a chicken or pork gyro. Admittedly this may have been due to my inability to read the menus. 
I did have plenty of chicken and pork souvlaki.
I have absolutely had gyros that were significantly better than others. Near me (Chicago suburbs), I have places that I know will serve a gyro with juicy flavorful meat and ones that will serves fairly dry and bland, though still edible, gyro. I find it matters a good bit if it’s sliced right off the spit when it’s ordered or if they use prepackaged, pre-cut strips that they just reheat. I’ve never tried a gyro outside of the Chicago area though so I can’t say if they all taste the same out in the hinterlands.
The “greek gyro” is lamb at Arby’s. It’s perfectly serviceable, if the nearest greek restaurant you know of is 300 miles away…
I used to live in a city neighborhood where the cozy corner diner was run by Greeks. They had a gyro meat omelet with tomatoes & feta that was fantastic. With tzatziki on the side and cucumber slices too. Their home fries had some Greek seasoning mix on them to boot. Ate that meal a lot.
If it was easy to buy decent gyro meat in small quantities I’d make those omelets here at home.
since lamb is pervasive in Greek cuisine, I can’t think why they would use pork
Oh, yeah. There was a Greek restaurant called Kostanarous near here that served an amazing gyro omelet.
Back to the original question. You would think someone would offer gyros with cilantro, thin sliced cucumbers, or hot peppers or something. Maybe a sprinkle of secret herbs. Those all sound good to me. The best gyros I have had, although they are still the exact same ingredients, have had tender meat (not dry) and lots of sauce. Did I mention lots of sauce?
Lots of sauce on the side or if you ask for it. I like to be able to eat a gyro without wearing a bib. A cup of sauce on the side would be great to dip it in while eating.
I’ve seen some sliced cukes on some, but it’s usually just lettuce and tomato, and a little bit of onion. I’m not sure what else goes there but cilantro sounds good, and maybe some thin slices of sweet peppers.
I do like the some of the pre-formed meat slices, but when I’ve purchased them at the store I think they were in the freezer for a long time and lost a lot of flavor. I’d have no problem making my own, it’s basically a meat loaf cut in slices that are then browned. I think the meat could just be browned in a pan without baking first and served in chunks instead of slices, but slices are better for holding together if you’re eating on the run.
Come to think of it, there is a food truck around here that gives you the option of ordering your gyro “spicy”, which basically means they squirt some sort of hot sauce on it along with the usual toppings. And they do add sliced cucumbers, and now that I’m looking at their menu apparently they include cabbage in addition to the usual lettuce, tomato, and onion, which I honestly never noticed before.
There’s a small chain of restaurants in central Florida called Louis Pappas. The only one I’ve ever visited is the one in the Tampa airport, at Airside C, which is the Southwest wing of the airport.
Their gyros are the best I’ve had. Most Greek restaurants have a serviceable gyro, as long as there’s enough tzatziki sauce. There’s something in the way Louis Pappas preps the lamb that makes it awesome with a modest helping of tzatziki, rather than having the lamb slathered with the stuff.
One of these trips we’ll have to try one of their restaurants that’s not in the airport.
A few years back a tiny Greek restaurant opened up in the Trenton area and I stepped in one day to try a gyro. The place was run by an old white haired Greek man and his wife, and they made the absolute best gyros. I would stop by there at least once a week, sometimes two times, to pick up a gyro. He ran the register and was always jolly and shared stories of how things were going, and his wife in the back always asked how I was doing and where I had been for so long.
If I took a month or two off for whatever reason, they would greet me with even broader smiles when I returned. She waved to me as soon as I opened the front door.
Then one day I went and the place was closed…and it remained closed for several days. I figured they had gone on vacation, so I waited a few weeks and went back–still closed.
After a month or two had gone by, I knew something bad had happened.
A friend knew their family and let me know that his wife was in hospice, and has since passed.
The restaurant never reopened. There is a different restaurant there today.
So sad for the passing of such a kind person and the loss that the husband suffered. 
And yet, they do.
Watch this video, for instance:
Note the description: “In general, gyros consist of juicy meat (pork or chicken) roasted on a rotating rotisserie.” The word for pork in Greek is χοιρινό, and you will see it in the menus. (Like at 3:12, the first gyros listed is a pork one, and the second is a chicken one.)
I’m guessing, for one, it’s simply cheaper than lamb. Even up in Budapest, the Greek places offered up pork and chicken, as that was the expected for the cuisine (sometimes you could find lamb.)
Where I come from, up in Edmonton, Alberta, there’s not many places for gyros (maybe Opa) but there’s lots of places for donairs, which I believe is the Turkish version of the gyro. I don’t know how much difference there is between the two, but they seem pretty similar. Seasoned beef (in the donair) sliced off a spit, flatbread, lettuce, tomato and onion with sweet sauce. Quite tasty.
As far as I know, the places I have eaten a gyro all used the Kronos meat. The Kronos posters are on the wall, at least. Despite this, the quality definitely varies from place to place. My favorite place is just called The Gyro House, which has been run by two different Greek families over the years, and always has wonderful gyros. I have eaten at places that had no Greek staff at all, and was sadly disappointed.
One place had huge soggy gyros that I was forced to eat with a fork because it was just falling apart. I think they must have pre-sliced the meat into a pan on a steam table, and added water throughout the day to keep it from drying out. They gave you a big pile of meat on the pita, very little tomato or onion, and if you were not absolutely clear with your order, they would put mayo on it instead of tzatziki. They went out of business fairly quickly.
Another place was staffed entirely by college students, as far as I could tell, and was trying to be hip or trendy. Their servings were small, bland, and overpriced, but they had great wifi.
So, my experience is that all gyros are definitely not the same. There is an Arby’s near me, and my wife likes the roast beef there, so I may try their gyros at some point and see what they are like.
The Arby’s gyro is an abomination. I have no idea what kind of gyro houses there are in NE Ohio, but damn, if it’s similar I pity you.
Or maybe they’re just not your thing, that’s ok. I love everything about Bloody Marys (the ingredients, the smell, the extras, the look of the entire thing screams Sunday morning hangover cure), but I have tried at least 20 over my lifetime and have never liked any of them.
Here’s my long-running get-rich plan: mini gyros rotisserie kits for the home. We’ll sell both the rotisserie appliance – maybe a quarter the size of the restaurant version? – and the corresponding meat cylinders.
Perhaps we’ll follow the inkjet printer or razor blade business model: break-even (or worse) on the hardware but then high margins on the consumables.
I’ve got no manufacturing experience. No restaurant or food service experience. No supply chain partners. And no intention of following through.
We’ll make billions. Who’s in?
You need to work on the plan. Try giving away the rotisseries, then they have to come to you for the meat. That’s where your real profit is.
Why would it be an abomination? It’s a traditional gyro:
I’ve had the Arby’s one. It was really bad compared to authentic gyro places. I was actually disappointed with how bad it was (I was thinking it may be at least decent). The meat actually felt somewhat leathery for some reason, I am not sure how anyone can equate the two to be honest.
IMO, the Arby’s gyro is probably the best entree item on their menu, and isn’t too pricey, though there are definitely better places in this town to go to for gyros (or shawarma, the gyros’ Arabic cousin, which is seasoned differently and comes with garlic sauce and tahini instead of tzatziki.)
The main differences in gyro quality generally are related to the bread and the tzatziki sauce. Excellent bread is a prerequisite to any great sandwich.