I’ve been thinking seriously of adding another ukulele to the herd. A tenor resonator, or resophonic, like the Kala shown above. That’s the re-designed 2014 model.
I’ve played earlier models, including the 2013 version with the strings attached to a tailpiece (see photo below, left). The 2014 design (shown above) anchors the strings back into the cover plate, which I expect will be a better design; it looks cleaner, too. But I believe the biggest change is that the through-the-plate model has more tension on the biscuit (see below). And I like Kala products, too.
I really like resonator instruments and currently own a Soares resonator tenor guitar. It’s lovely; all-metal body, but a heavy beast (20lb or so)
I owned a Republic all-metal reso uke, a few years back, but it was concert scale. Interesting uke, but I didn’t keep it. I loved the look, but I don’t like concert scale as much as tenor, and I think that concert scale strings don’t put enough tension on the biscuit to make the cone work effectively. However, it gave me some ideas about improving reso uke output.
In the physics of guitars and ukuleles, the more tension on the saddle, the greater the energy passed along through the bridge to the sounding surface (top). Thus the greater the tension, the louder the sound and the greater the sustain.
A tenor uke has more string tension than a concert, and because of this it is this is generally louder and richer in tone than a shorter scale uke.