I also have a selection of Vintage DD TT's imported from Japan, and have a few en-route at present.
I am happy to use a simple Walwart Step Down Tranx when getting the early impressions of a TT. If it becomes one I am interested in for further investigations, it will be converted to 230V.
These TT's are usually purchased under the impression they are wanting in some way, which all have proved this to be the case, and the TT's are not in the same price bracket individually as a SP10 R. I can't but help feel, I would want to have the R, if it was reliant on other ancillaries to produce the correct working Voltage, having the R work with the supplied Mains Voltage would be my preference.