Not really helpful but this is my experience.
I tow a 1340kg mtplm Avondale with a 1.8 petrol Mazda 6, max tow 1300kg.
The car is only 118 hp and max torque is @ 4500 rpm so is really a bit under powered when towing.
It is however very stable when towing.
The only problem I have encountered is some inclination towards wheel slip on hillstarts.
The diesel has more power (unless you have the poverty 119 hp variant) and the torque is far superior and peaks much further down the rev range, about 2000 I think it also has a max tow of around 1500kg.
The only real problem that I'm aware of and,it is hearsay rather than personal experience, is the clutch. Apparently ALL Mazda clutches are considered to be too weak for towing.
There is no heavy duty upgrade available and as the fly wheel on the diesel is of the dual mass type it MUST be changed at every 2nd clutch plate renewal.
Mazda ^ is an excellent car and was only let down in the 2006 towcar of the year awards by the amount of clutch slip necessary to prevent wheelspin on hillstarts.
GO FOR IT.