Hi Nicola
I was on the Lake Garda/Opera tour last summer and it was fabulous.
At the Opera the majority of the group opted for the seats on the stone steps rather than upgrading the tickets for the more comfortable seating areas. It wasn't particularly comfortable as I had made the mistake of buying a cushion outside the arena rather than inside, and you are sitting for more than 4 hours.. The group was split up as well as we were among the locals and other tourists. It was also quite high up but you got a good view of the stage and the set was amazing.
The numbered seats are lower down and on the floor of the arena in front of the stage. There was a short shower just after the first act but the Opera continued with shorter or no further intermissions upon the restart.
The night of the Opera was on the Saturday, which was also the free day.
I will certainly recommend this tour.
James