Hi,
We tow a 1600kg Lunar Lexon 640 t/a with a 2.0 tdci S-max though it's unlikely that we ever load it near it's mtplm, we find it to be very stable and unaffected by passing hgvs and all but the strongest of crosswinds, towing mpg is 26-29 and solo mpg is 40mpg in a hilly area, we got 52mpg touring Norfolk for a week, we frequently meet up with parents so there is plenty of room for 4 adults 3 kids and still space for two labradors in the boot.
Being just fwd it's achilles heel is traction but so far we have never needed to use our snow/mud chains and you won't get the same fuel economy out of a 4x4 thhat has as much interior space.
As a solo family car there is nothing to touch it for practicality, fun to drive and running costs. it looks more like a hatchback on steroids than an MPV, handles like a GTI and the new 2.2tdci must be even better.