Brenda,
We've had our S-max for a year now towing a Lunar lexon 640 twin axle 1266/1600kg unladen/laden, solo I would agree with everything Icemaker has said, the way the car handles puts a silly grin on my face like no mpv should! the problem with "kangarooing" I think is due to a poor response curve on the accelerator pedal ie depressing the pedal 10% gives about 90% of the available power and it's difficult to balance it between stalling and wheelspinning in 1st gear, it gets better once you get used to it, my 03reg transit tdci 125hp is much better. With 20 k on the clock we are getting low - mid 40's mpg solo and 26 - 28 with the lexon on the tail, on a week touring Norfolk we managed 52mpg over 300 miles.
Towing it is easily the most stable towcar we have had, better than the Transit or our old Sharan, the most surprising thing is that I expected problems with crosswinds with such a large van on the back but moderate crosswinds and hgvs cause barely a flinch.
Hopefully the reliability will be better than the Old Galaxy and its sisters, by 115miles our Sharan had blown a head gasket, air con,wiper motor, wiring, suspension joints etc had failed, my father in laws galaxy had a new auto box at~35k amongst many other faults, he's now looking at an S-max.