JoeJoe wrote:
particualrly loud during the phase immediatelly before the final spin - I
assume it is called something like "balancing the load" or similar. It is
basically when it spin very slowly from side to side for a short while. It
also makes quite a noise during final
spin.

There are a few possibilities. The balancing system comprises of some
heavy weights, springs and dampers. If any one of those bits has come
off, it will do odd things

I really cannot see myself opening the thing to try and fix it myself, but
are washing machines in general worth fixing in terms of value for money?

It could be something completely obvious like a detached spring. Worth a
look...

PS: the machine has had a hard life so far with two young children in the
house - probably an average of at least one wash a day since it was bought.

Check your warranty details. A lot of high end Bosch / Siemens
appliances come with 5, 8 or even 10 year warranties.

My Siemens washer has a 10 year warranty and my dryer a 5 year one.

Steve