I've done the TransAm/Northern Tier (on the west end) self-supported, and about half a dozen supported trips, ranging from we'll truck your tent and bag (AC Blue Ridge) through we'll set up your tent (Cycle Greater Yellowstone, now Montana Cycling Project) to motel to motel (x3). One nice thing I appreciate more as I get older is having a shower at the end of each day's ride to wash off dirt and sunscreen; all of those except the self-supported had that.
I had to chuckle at the young whipper-snappers riding long distances every day. IME, the average age of the cyclists was probably two decades older on the supported tours than on the TransAm.
It's a bit of luxury to have not only the routes laid out, but also SAG (with water) stops every 1-2 hours. Same with sleeping in beds! And there's a wide variety of price ranges available; for instance, the motel PacTour ride was less expensive than the CGY with tent sherpas.
I tend to be relaxed about food, IME it's always good as long as there's enough to eat on tour. Beware of local business catered meals in small towns; they don't always appreciate the quantity of food a horde of cyclists can eat. OTOH, a church had a dessert bake sale the afternoon we rode into one small town. Heavenly cherry cobbler with ice cream! The spread the ride put out that night was good, but I didn't appreciate it after snacking on two and a half desserts that afternoon.
It's a question of what you want to do, and how much you're willing to pay for it. One week and you want to ride a place (Blue Ridge Parkway) or an environment (northern Wisconsin to get away from the heat of August)? Write a check, show up with bike and bag, and enjoy the ride. Every organization I've ridden with knew what they were doing, and knew that taking care of riders was the way to get more business. Want to go to someplace the rides don't go? Either figure out your route and make the reservations -- a good way to spend a cold, dark winter weekend -- or, if it's close to a place one of the "variable" groups ride, see if they'll go through there next year. Looking for rides in the wilderness? That's probably going to be you carrying all your gear, possibly with a few like-minded friends. (Although Beartooth Pass or Skyline Drive don't see many buildings!)