Since we live in Utah, we have never taken a guided/bus/coach tour of Utah, but on our travels around Utah, we have run into plenty of people on guided tours, and from what we know about guided tours in Utah, there follow some hopefully useful thoughts.
Bryce
Utah toursim has some quirks, like the town of Kanab. Famed tour book author Arthur Frommer wants tourists to boycott Kanab. The City or county council of Kanab endorsed a local ordinance a few years ago declaring that "A woman's place is barefoot in the kitchen raising a full quiver of children." Kanab has fewer than 5,000 residents and 52 motels. 80% of the people who stay overnight in Kanab are foreign visitors to the USA. They know something most American's don't-- Kanab is less than a two hour drive from Grand Canyon National Park (6,000,000+ visitors a year; Zion Canyon National Park, 4,000,000+ visitors a year; Bryce Canyon National Park (1,000,000 visitors a year); Escalante- Grand Staircase National monument (1,000,000 visitors a year). Kanab is the largest city in Kane Co., UT, which has a population density of 1.52 people per sq mile. One of our tour guides in China told us he was saving his money to go to Texas to see where his favorite movie, Giant, was made. I enlightened him, "Giant was filmed in Kanab, Utah. Don't go to Texas".
Fall
All roads in the American southwest lead to Kanab if you are taking a guided tour. The only road in or out of Zion National Park passes through the town of La Verkin where you can be arrested should you reveal the UN Flag in public and a nearby village where all adult residents are required by law to own a gun,
Here are some tips on selecting an itinerary, but first, some important advice on what gateway cities to avoid:
1] Phoenix is the worst place to start a tour. I've been to Phoenix many times, mostly on business, and the only thing of any touristic interest in Phoenix is that it is the ugliest city in North America. Not to mention that summer temperatures, which is when tours run, are intolerable.
Most tours get out of Phoenix as fast as they can and go to Sedona. Why? Because Phoenix is the ugliest city in North America and, as scenery in Arizona goes, Sedona is a gem. As Utah scenery goes, Sedona is second rate.
2] Salt Lake City is also a poor choice from which to start a tour of Utah, although not as bad as Phoenix. Salt Lake City's problem is that it is a tourist's nothing burger. It is a moderately attractive city due to the very wide streets the founder of Salt Lake City established, declaring the streets should be wide enough that a 12 ox cart should have a street wide enough to make a U-turn.
Utah has three geographic zones, 1) the West Desert (the Bonneville Salt Flats); 2) the northern mountains (up to 13,000+ feet); and 3) the Colorado Plateau (see Triptipedia post on the Colorado Plateau). Your tour wants to get you to the Colorado Plateau as fast as possible, so it will skip the spectacular scenery of the Northern Mountains to get you to the Colorado Plateau as fast as possible.
3] Many tours start north of Salt Lake City, in places like Rapid City, South Dakota, and Bozeman, Montana, to take in Yellowstone National Park and Grand Teton National Park on their way to southern Utah's Colorado Plateau.
On a one week trip, this is bad idea because it takes a day and a half or two days to get from Grand Teton National Park to the Colorado Plateau. And you will invariable have an oven night stop in Salt Lake City, a good destination only for catching up on your sleep.
A brilliantly planned tour will skip Salt Lake City and instead take you south through Dinosaur National Monument. I don't know if such trips exist, but they should. They should also leave Grand Teton National Park by Hoback Canyon and also visit Fossil Butte National Monument.
Bald Eagle
4] Las Vegas is in many ways the best place to start and end a Utah tour because you can do a loop through all five Utah National Parks, several National Monuments, and take in monument Valley, Navaho Reservation, Navajo National Monument, Petrified Wood National Park, and the Grand Canyon South Rim going to or from Las Vegas. Not to mention that Vegas is one of the world's top tourist cities, an absolute must see for at least two days.
Many tours end in Las Vegas, but add 2-4 days.
5] Denver has good air connections to Europe because it is a major Star Alliance hub (United and Lufthansa). A tour starting in Denver will show you some great mountain scenery on the way.
Some Things to Know
Around Christmas is a great time for bargain travel, but hard to find tours. Las Vegas and all the above mentioned sights in Utah are in a desert. It rarely snows in desert. We've been hiking in Zion National Park on Christmas day dressed in shorts and tee shirts. There will be a little snow on the ground in at Bryce Canyon National Park.
Capitol Reef
What is a National Monument? It is a National Park with a different name. Both are operated by the National Park Service. Both have crumbling infrastructure because the Tea Party Republicans and Moscow Mitch refuse to pay for proper upkeep. Congress has to create a National Park. The President on his own can create a National Monument under the provisions of the century old Antiquities Act, but when it comes to great scenery, there is no difference. .
What is the Grand Staircase? You really need an airplane to see this, but start at the bottom of the Grand Canyon, about 600 ft above sea level. The first step of the Grand Staircase is from the bottom of the Grand Canyon to the North Rim at 8,000 ft above sea level. The North Rim plateau gradually dips down to Kanab at 5,000 ft above sea level. The White, Gray, and Pink Cliffs lift back up to 9,000 ft above sea level at Bryce Canyon. The last step is to 10,000 ft above sea level on Boulder Mountain/Aquarius Plateau. The Boulder Mountain/Aquarius Plateau is so big (it is about 80 miles long on its eastern edge) that it was discovered twice, once by explorers coming from the south, and once by explorers coming from the north. The south guys named it the Aquarius Plateau. The north guys called Boulder Mountain.
