I did a 12 day, 7 country Contiki bus trip around Europe in 2006. Defiantly a reputable and great company to travel with. I was a solo female traveller and really enjoyed it.
The trip I was on started and ended in London, at a hotel near Russel Square. Contiki offered a discount for pre and post trip rooms at the hotel, not sure if that still happens.
The trip I was on was mainly Canadian and Australian people mid 20's, early 30's. Everyone on the trip except me were with someone, either couples or friends travel buddys.
The itinerary I went on was intense, we had a departure time of 7.30am every morning, no matter how late the partying the night before. The first few hours of morning travel was usually people sleeping off hangovers. Some people did more partying than others, remember that the legal drinking age in Europe is 18. Generally though there was no excessive partying, everyone made the departure time every morning, I dont think we were more than 10 minutes late leaving an morning.
On the bus there is 1 driver and 1 tour assistant, they are not guides. I got lucky and the tour assistant was very enthusiastic and involved. For every stop she had a general info handout and a suggested touring plan. You were under no obligation to join the group touring plan in the cities and towns. Some of the attractions had an additional charge, some did not. All the information about the additional charges was available on the website before the trip. I did my research and knew exactly which extra charge attractions I wanted to see. That way I was able to budget and keep that money separate from my own daily spending money.
Most of the places I did a mix of staying with the group and exploring on my own. The only rules about the free time was that you had to be on the bus by the departure time the next morning.
The accommodation was a mix of mid price chain hotels and independent family run hotels. As far as I can remember breakfast was included and provided at all hotels.