As has been said. . . it's personal choice.
We chose NOT to carry a spare to begin with. We took a nail in a tire on our 40' Phaeton at 2:30 in the afternoon driving through the Ocala National Forest. Our rig was about two year old. When the road service contacted us back, she told us the tire guy said our 2 year old tires were obsolete, unavailable, and they would not be able to furnish a matching tire. So they wanted to bring us a brand new different branch tire for $600. We said no, bring us a used tire. So we sat for 8 hours while the "service guy" located a tire for us. In the meantime, I called Michelin and asked about our obsolete tires. They said, "What? No way." In fact, 22 miles away from us in Deland, Florida, was Boulevard Tire and the computer showed they had over 200 matching tires for us. Boulevard Tire does not work with most road services because of the way payment is done, etc. Suffice to say, had we known this and called Boulevard Tire, they would have dispatched a truck and within 45 minutes our tire would have been plugged and patched and we would have been on our way. Instead, there we sat waiting. When the guy got there, his used tire was in such bad shape with a "repaired" sidewall, he couldn't get it to seal on our rim. Eventually he did, but he said our other tire was ruined and he would just take it off our hands. We said, "No, we are keeping it."
Following Boulevard Tire's instructions, we drove the 22 miles to their facility arriving at 10 p.m. and boondocked in their back lot. At 7:30 in the morning, they came out, removed the used tire, took our other tire with the nail, repaired the (nonrepairable) tire and sent us on our way. We got another 50,000 miles out of that tire.
So, we now choose to carry an unmounted spare. . . always will. Don't need to be at the mercy of those charlatans who just want to screw you out of your hard-earned money.
Dale