I have just got back from this trip, we had a fantastic time. There was a wide age range and different circumstances to be travelling alone. For the majority it was their first time travelling alone but I know that most will now do so again!
The only bit that I was worried about was the airport at the beginning as you dont know who is also on your tour - although there were one or two who had put their spare label on their hand luggage which helped me to approach them. Once we were in Italy and on the coach everyone just got on and you never felt as though you were alone.
Go for it, you will love it!!!
Lesley