Could have chosen better hotels and timed the traveling between cities more efficiently.

It was a great experience to see and feel Japan at it's core. We absolutely delved deep in to Japanese culture both modern and ancient.

This was a great introduction to Japan. The trip was the perfect length of time to visit each location and see the best each location had to offer.
Tokyo - wonderful! What can I say? I recommend you add on a day or two (or more!) if you want more time to explore Tokyo in more depth. I added 3 days on. Recommend: Shinjuku, Golden Gai, Shibuya, Asakusa and Harajuku.
Takayama - a much quieter mountainous town where we stayed in a ryokan. You will be sleeping on a futon on the floor. We did so many things in Takayama it felt like a blur. Make sure you have lots of energy for the day you wake up in Takayama to travel to Hiroshima as it is a huge day of both activities and then travel.
Hiroshima - the absolute highlight of the trip for me. Beautiful weather and a totally different feel to Tokyo, Osaka and Kyoto. Miyagima was perfection and is a must-see.
Osaka - more gritty and nightlife-focused place. Unfortunately, I was unwell and so couldn't take advantage of all that Osaka has to offer but I made the best of it. Osaka Castle is magical. I didn't go to Universal Studios Japan but those of the group who did go loved it.
Kyoto - absolutely loved Kyoto. We had many great things to see and do here. The only gripe is there's so much to see, and so little time! I'd recommend if you are into more traditional Japan culture to add on days at the end of your trip.
My group was friendly and everyone got along really well with each other.
The accommodation was good quality - with a mix of modern hotels and traditional ryokan (1 night).
Travel was mainly by public transport, taxis where needed, and walking. Shinkansen was a great experience. Be mindful that your larger luggage will be sent on ahead of you, so that you can easily catch trains to your next destination. This is a great solution to having to carry around a big suitcase. Just make sure you bring a decent sized backpack on your trip as you will need it to store 3 days or so worth of clothes etc.
Bring good, comfy walking shoes that you can easily take off and put back on again as there's some places you are required to take your shoes off. Bring your professional camera (if you are a more advanced photographer) or your best smartphone to take amazing photos!
Make sure you bring as much cash (yen) as you plan to spend. Cash is king in Japan. You can pay for only some things (e.g. convenience stores) with credit card. It's just easier to bring cash - especially for meals and souvenirs.

Had a good time. Katherine our tour guide was great and really helpful. Just be aware though that Japan is not very vegetarian or vegan friendly so that was a bit of challenge. Katherine however had some good recommendations and did everything she could to ensure my dietary requirements were accommodated as much as possible

Great experience, a little experience.

I had a fantastic trip leader (Marion) she did a great job with taking us from place to place on the trains. All our hotels were amazing and clean and in a good location.

Regarding where this tour takes you, it ticks all the boxes. While there could have been some rearranging with how long is spent in different places, I loved every city we travelled to. Like I said before, all of our inclusions were cancelled due to it being peak season (no excuse as I have been to many places with Topdeck during peak season and this was no issue) so we had to research and come up with our own ideas. While this worked well for me as I love a bit of freedom with travel and wasn't interested in some of the inclusions, I do feel as though the things we did in our free time could have been inclusions. There are so many opportunities for unique experiences in Japan, so making them inclusions would just be beneficial to everyone. While it was annoying we weren't informed that we would be without our suitcases for most of the trip (again, better forward planning from Topdeck is needed here - just put it in the Trip Notes!), the service of sending our luggage ahead make travel by train so much easier. Japan is a busy and crowded place, so I understand that having a typical tour experience where we get a lot of information about each city might be difficult to do, but I really missed that part of the tour because I like learning about each place I am going to. It's a great trip, but it is really up to you and your friends to make it great.

I didn't purchase anything from the tour [other than the tour itself] as the options were cancelled for us

The Japanese tour it was so much fun. It was a really good mix of culture, food and free time. I like how they gave you time to go off and do your own thing in the city for a few hours so that you could plan a trip more to your liking, and not just what their planned in the tour. Is what you were allowed to do. My tour guide Marion was funny and amazing. She really helped us with getting around, restaurant recommendations, things to do in the city if you weren’t unsure. Also a big help with us getting train tickets to get back to Tokyo after the tour, I would would have been totally lost. The one thing the was a minor problem is that Topdeck didn’t warn us before hand that our suitcases were being forwarded to other cities. As we were going by public transport, which was really fun doing all the bullet trains however, it was a little hard carrying a heavy duffel bag everywhere. I would recommend to bring a smaller rolling case like the one you can use on planes it will make such a difference not carrying that.

all good, just didn't know that all the optinal activities were canceled

I would definitely recommend this trip. Marion, our trip leader was great with giving us ideas on what to do on our free days and booking group dinners.

Topdeck’s communication can most definitely improve. It was disappointing to discover on the first day that all of the optional activities were fully booked and that really they should have been booked by traveler's in advance. TD should have communicated this in advance or in the trip notes to avoid disappointment. Additionally, there was no mention in the trip notes that we would not have access to our luggage for two lots of 3 consecutive nights meaning we needed a backpack or smaller bag for these nights. This is because, our suitcases were shipped to the different cities. Rather, the notes state you need to make sure your suitcase is less than 160cm to be able to take on the bullet trains, which we didn’t even do. Not everyone had a backpack which meant they had to go out and use their free time to find one. If TD updated the trip description and the trip notes with this information then it would have made the trip so much easier and less disappointing.