I have to say that although I still like my S40 and enjoy it - it has taken a LOT to get it 'right' over the years.
Suspension is a massive ballache and very tiring in terms of near constant replacing parts of it, numerous 4-wheel 'alignment' attempts etc. Mine is about right now and I can probably say that 85% my suspension is under 5 years old (2005 car).
I've just google imaged: 'Powershift Gearbox Explained' and it looks a very complex unit.
I then did the same for the VAG DSG box and it looks quite similar
As far as I've heard the VAG DSG is quite reliable but also requires regular fluid changes - as does everything.
I think for an easy life I would prefer an old school torque-converter automatic, says he who also owns a Citroen fitted with an updated version of Fiat's 'Selespeed' (remember those) gearbox which is a Robotised Manual
we've put 50,000 miles on it and it's been faultless