While I have a few more questions that we are waiting on answers from Seiko Japan here are a few that may be of interest for GS owners or potential owners here in the US. Since there seems to be some discrepancies on these topic these are the words right from Seiko US. It is really nice to have a direct channel for these things:
Can any of the Spring Drive or High Beat watches be serviced in the US? Yes All GS calibers with the exception of the Spring Drive Chronograph 9R86 can be serviced in the US.
For Japan and US service what is the general turn times to complete regular maintenance? For the US, we do not have an answer at the moment because this is very new for us. Only recently was one of our craftsmen certified to repair and service Grand Seiko. He spend many months over 2 years studying, practicing, taking examinations and travelling to the factories in Tokyo before he could be certified.