it looks like the refills are available from NWB in Japan too...
part numbers:
DW45GN = 450mm
DW48GN = 475mm
DW53GN = 525mm
if you're unsure which one you need, looking at the mounting bracket may help:
NWB says that graphite coated rubber, reduces rubber wear, as well as streaking, and chattering when the wipers are used on Rain-X (silicone water repelling) coated glass. They also say that it also helps reduce the tendency of wearing off the coatings, thus making them last longer!
http://www.nwb.co.jp/products/pdf/graphite.pdf
so definitely, these Supergrid Aero wipers were worth it. I think it's worth maintaining them with refills too...
so how about a GB with rupe for those refills?