Hi steve,
I'm not really an upright player either, but having sat the Ash in my lap and played I can see that the position may have certain benefits. But i'm happy without frets as my usual player is a '69 Fender precision fretless (can be heard on the following track @ myspace). Playing a few instruments, one of the things i'm intending to do is to have the Ash standing in an upright position and play through a looper. As it will be poised in a playing position I will be free to do other things around it and come back to it...work in progress.
My playing nowadays tends to be of a slightly jazzy/arabic, world fushion type, which the upright sound seems to fit well with, my other main instruments being Frame drums, Udu, some guitar, keyboards and voice. I also used to play in a reggae band, about 20 years ago, in Manchester. Also played in soul bands, and I have to say I like the feel of a large band.
Can't say i've noticed a hum, but nice to know there is a fix possible if it develops one in the future!
Did I see somewhere else that you are using those Pahoehoe strings? Are they the same size (gauge) as the Fenders? I'm just considering the possibility of building something similar with maybe 5 strings and whether the two types of string could be combined to provide a wider range.
many thanks,
tiwie (it's another steve, but my little nieces pronounciation!)