We have used Xpress travel now for nearly two years. They have trouble at the start of the year - first few weeks in September - because unfortunately parents have become complacent. They ask for the forms to be returned so that they can plan how many DC's are getting on at which bus stop. Parents send their DC's to the bus stop with forms in hand and wanting to get on the bus - this causes chaos for them. DC's also get on at different bus stops (because parents drop them off at mates houses) - again causing hassle for them. We have never had problems with them after the initial "teething problems" at the start of every school year.
They have recently bought new busses and are expanding their service (airport runs, hen/stag nights, dog racing, etc). All their buses have seatbelts - but it is up to the child to wear them. Crypt have sent a few letters home about DS's not wearing seatbelts and misbehaving on the busses - these will probably get thrown off a public bus
They have also put on minibuses which have dropped DS's off nearly outside our house, instead of the bus stop, and given out icecreams on hot summer days so my DS's are very happy
We have looked into alternative transport (Bennetts, Marchants and Stagecoach) but they are cheapest for us in Longlevens. Looking at the bus drivers from Bennetts who drive for Denmark/Tommies I would definitely want my child to wear a seat belt - they drive erratically and have no respect for other road users at all