Whatever the S in S Stock stands for it's certainly not Simple Seats.
The driver's cab has a lovely new seat but it has a complex mechanism - in fact, several complex mechanisms! - for adjusting its height, footrest and distance from the handle.
This would not be a problem if only management had bothered to provide training for drivers in how to operate it to ensure that it is ergonomically correctly positioned.
No such luck. So when drivers complained of discomfort (numb bum syndrome), the train manufacturer replied that the drivers were not positioning it correctly. Worse health problems eg. frozen shoulder could follow if this is not sorted out.
Once again, management's unwillingness to spend any money has proved to be a right pain in the backside for staff.