So long as you have sufficient power to avoid gear hunting on slight inclines and an appropriate amount of oil cooling then automatics win over manual gearboxes in my opinion. They are less stressful on the vehicle and on the driver. The other issue is whether or not the towing vehicle is heavy enough to make for less exciting braking and stability - here larger cars, which are often automatic, score again.
A final observation: automatics are a lot smoother to draw away on slipways.
Pat.
__________________
|