I decided to send the router back to Bosch.
I was already exchanging emails with the manager of the service section (about my experience of their service levels), so I let him know the router still had an electrical fault, even though it carried an electrical test "pass" sticker from their last repair. He asked me to send it back for re-inspection and mark it for his attention. The Bosch policy is to offer a free pick up from the customer using Fedex, so I sent it back on Tuesday (14th).
I was surprised to see a van backing into my driveway today - a "cheeky" Fedex driver! My router has arrived back only three days after I sent it. Bosch aim to turn items round to the owner in 5 days, so they must have rushed it through. Allowing 1 day for transport each way, they must have turned it round in one day at their end.
It's been repaired,
free of charge. The invoice that came with it shows a new armature and bearing have been fitted, which I know from previous threads are in the order of £190, so with the labour it would have been over £200. Also, this time they sent it back with a decent level of packaging, not perfect, but much better than last time.
So in the end, I didn't need to kick up more of a fuss, although I was prepared to.
There was no note with the router when it came back, and I haven't had any email from the manager either, the router just arrived back out of the blue (not that I'm complaining). I would have thought they would want to be able to say "repaired free of charge, to make up for your previous experience" etc, etc, but it looks like communication isn't their strong point.
All's well that ends well.
Steve