I own one of these: http://www.acousticmagazine.com/reviews/gear-reviews/vintage-viaten/
Which I bloody love! I play double bass in a folk band, but we often get random tiny gigs (aboard old ships, in tiny folk clubs, in dylan thomas' old living room).... And for that it's perfect. I also play bass for some singer-songwriters, and this adds a nice extra dimension to songs that don't need the low end.
I tune mine GDAD, which is an octave lower than a mandolin (Which I also play a bit of in the folk band), but with a D on the highest pitched string. It gives a great open sound, very mellow, very full, but quite different to a parlour guitar or folk shaped guitar. I definitely recommend open tuning for the instrument as it just sings.
The viaten is amazing bang for buck - I played a few different makes before choosing a "cheap" brand, and this just sings. I'd love a 1930's Martin tenor, or custom archtop, but for less than the price I charge for a day of studio work, I got an amazing instrument.
Bloody love it.
edit for shameless folk band plug www.captaincat.co.uk