Is this viable and/or worthwhile for new or nearly big Jap bikes? Anybody doing it? Anyone have any experience? Where from East or Europe?

No, not really, if you shop around (especially at this time of year) you'll get just as good, if not better deal from an official dealer.

All my new bikes have been imported.
If your buying a new one nothing to worry about the only thing your miss is a factory warranty but most importers give at least 2 years warranty.
Depending on the yen you can pick up a bargin. The most i've saved on one bike was £2000 so do your home work before buying.

pm me & i'll give you some dealers who can save you loads of money.