I used to chauffeur drive for a Luton based car company with offices at Gatwick, Man, BHX. Most of our work was crew transfers all over the country with major contracts for the likes of Thomson and Easy Jet.
We also did Cruise transport either from Home or Port. The vehicles used were Mercs and Merc vans. It always amazed me how much luggage people took on cruises.
I would suggest using a car service... at least then it is door to door and if your flight is delayed then the driver will wait. Definitely less stress and lugging bags aorund from plane to bus, Bus to train, train to taxi..... why start a holiday with all that?