I know there are a few UK owners here, so I'd like to record my experience of a service by Swisstec, which is the BALL official service agent for the UK. It is actually part of the Omega agent Swiss Time Services. It shares the same building and atelliers.
I sent mine away at the beginning of June, and had an e mail estimate the next day, and a hard copy in the post a day later.
My watch, an Engineer II Master diver Worldtime, had two issues; the world time ring was not moving in synch with the analogue hands, and a tritium vial had moved on the minute hand.
The estimate was for a complete disassembly and re-build service, new hands, new world time ring, and a re-finish of the case to factory condition. The watch would be subject to a 48hr timing test. Cost was £270 including VAT and RMSD delivery back to me. The time to complete the job was quoted at 20 working days, ie, 1 calendar month, and it actually arrived back in 19 days.
The watch, after 1 week is running at +1 sec/day, which is much better than I expected, ie, it is more accurate than my Hemble Mad Cow, which runs around -3 secs daily, which is a real pain. The case did indeed look new, and much better than it's pre service condition.
It came back in a spiffy 'Ball' hard case, but with a padded interior, which was excellent, because I had lost the original case.
Overall, a very nice job. by a class act company. A tad expensive, and a bit slow, but ultimately worth every penny. Well done Time Services - a good expeience.