Recently returned from our trip, and since there is scant information in the forum on this particular trip, I'll share what I can.
We were on the last trip of 2023, with a departure in late September. The tour is for a small group of up to 18, but we only had eight total guests on our trip. This was nice as we all ate at a single table for all our meals, along with the TD.
Vehicles - I've read elsewhere on the forum that K&T safari vehicles typically have side windows and pop-tops, while those in SA are open-air. We had a mix of both on this tour. For the first two days, we had the pop-tops for the visit to the Maasai boma and the Ngorongoro Crater. For the rest of the tour we had open-air vehicles until Nairobi. According to our TD it is largely dependent on distance to be driven. The walled pop-tops make sense when traveling longer distances, especially on real roads, which is why we used them to travel from the airport to in the crater since we stayed outside of it and had to drive a bit. Once we were at our camps, we were already in the Serengeti/Masai Mara, so open-air vehicles were appropriate.
Luggage - Unlike other EA tours, the only piece of luggage on this tour is a single duffel. It is much larger than those on the other K&T tours and we had no issue with space. My spouse and I each had a smaller duffel we took as a carry-on on the outbound flights but was small enough to fit into our larger duffels once we reached Tanzania. Nearly everyone just had the large duffel and a backpack/day bag. No one brought or had traditional suitcases.
Flights - There were a few internal flights on the trip, mostly in 12-person Cessna. One from the crater to the northern Serengeti, three flights in the same morning to travel from the Serengeti to the Mara (one to leave Tanzania, one to enter Kenya, and one to get to our Kenyan accommodations), and a final flight from the Mara to Nairobi
Accommodations - These were excellent. We got in late the first day, so I do not have much to say about Rivertrees, but the other locations were top-notch. All three of the places we stayed had individual cabin/tents with adequate distance between them to feel private. All three of the main accommodations provided laundry. Kitela, the first, was the only one to charge ($1/item) and also the only one who would do undergarments. Laundry was complementary at the last two locations in the Mara and Serengeti. Kitela and the Mara locations were both more established with paved paths and permanent structures. The Serengeti camp is mobile but still luxurious. All the tents had electricity, a shower, and a flush toilet. Legendary Serengeti does not have a wall, so an escort is required in the evenings and the nocturnal sounds of wildlife much more pronounced. Wi-fi was strong and available at all accommodations, including in individual rooms.
Wildlife Viewing - We had tremendous good fortune, with sightings of all the Big Five and other memorable experiences. The location of the camp in the northern Serengeti was particularly nice as it was much less crowded than in the South near the crater or across the border in the Mara. This permitted a much less crowded safari with fewer vehicles from other companies.
Food - Very good, particularly at the mobile camp in the Serengeti. It sounds absurd, but the croissants there were better than those in France. As with any Tauck tour, you won't go hungry, with snacks provided on game drives just when you think you might become a bit peckish. Arusha, Kitela, and &Beyond all served meals buffet style with plenty of options. The Legendary camp in the Serengeti was served family style. Kitela provided options for guests to pack their own lunch for the day in the crater. On the last day of the tour, both lunch and dinner (off a menu at your leisure) are provided at the hotel in Nairobi before flight departure
Shopping - This tour was very much focused on wildlife. There were only a few opportunities for shopping on the tour, once during the visit to the Maasai boma in Tanzania, at the hotel in the Mara, and then on the last day, we stopped by a large gift shop in Nairobi before going to our hotel.
Transit through NBO - Not strictly related to the Great Migration, but I'll share it here in case anyone searches for keywords in the future. We had no issue transiting through NBO on our way to JRO. We had a slight concern we would need a multi-entry visa for Kenya due to vague wording on Tauck's site, but that was not the case. Upon arrival, we went toward international transfers and away from the passport control line. From there, we went through security and then were in the international terminal. Apparently, even if we had needed to show our visa, it would not be an issue, as a single-entry visa is valid for three months of entries as long as the individual does not leave East Africa. FWIW, arriving at JRO from NBO was nice as it was a smaller plane than those arriving from Amsterdam. Landing to meeting our guide took fewer than 20 minutes since there were simply fewer people to process.
Please let me know if there are any other questions I can answer for future GM travellers!