Day Trip: Cambridge from London

Cambridge is fairytale and worth visiting, but everything else is so underrated: transportation is very poor, guided tour is waste of time. The bus was very uncomfortable, with annoying noise from the AC all the time. Instead of 6pm we got to final destination at 7:30 (the explanation was heavy traffic, however, I believe it's not the first time London has heavy traffic, so it could be taken into account while designing the offered tour, we had a dinner resevation at 7pm, that we missed because of wrong timing. Overeall, the experience was bad, there is no guide in the bus, only driver, in that case at least the driver could have given some general information (i.e. how long will take the ride, etc.).