I have been playing a Washburn 12 string for years now and have always tuned it into standard tuning using light gauge strings. It always holds its tune even when using a capo and has the benefit of a really good low action which I never found on other 12's I've owned. Overall its a really great instrument despite its great age. I did a bit of rebuilding work on it to get it to its current state which has proved worthwhile.
Pete