We have no issue with the seats, ours seem really adjustable.
As above though, it did take a while to get them set up correctly compared to the Golf GTi seats.
Once this is done though, it is a comfortable car. On a long run, especially cruising in 8th gear it eats the miles up.
It's a shame that the UK spec 128ti didn't get the same bucket seats as the M135i xdrive.
In some countries these seats were an optional extra.