The radio sets make a fundamental difference with the quality of any of the tours. At the beginning of this tour, 1/3 to 1/2 of the group could not hear the tour operator and the response I was given was to let the company know almost as if they had no control over the headsets. I cannot believe the company is allowed to continue giving a tour that people cannot hear.
We loved the Acedemia and it's well worth seeing the orginal David statue, and the unfinished sculptures. The guide we had spoke very quietly and her accent was strong, so didn't always catch what she was saying - it would have been better if she had explained what the tour entailed and be clearer in her directions for moving on - however it was difficult as people kept joining the group after we had started.
Tour was good and very interesting. The documentation from viator was however dissapointing. You will get an email with the rough information of the tour with a nested link to a voucher that has more detailed information. All that didnt however explain where exactly the group meets and who executes the tour. Viator is just a broker who engages with local tour agencies and you need to check with all of them showing up at the various gates at the Accademia. Once you know that, you can enjoy a 50 mins tour and have way quicker access to the museum that if you buy the ticket at the museum at which you have wait times of one hour or more.
The museum is great and seeing David along with some work in progress from Michelangelo with the professional explanation of tour guides is an experience that justifies the 20 EUR per person that this tour is more expensive than just the ticket without tour.