I've played all the available 30 series models, both at winter NAMM and summer NAMM. They are changing some things about the finish. At this point they are pretty much a gloss finish (at least the ones at the summer show), but you can still see grain dimples through it, so its very light. The next run is supposed to have a lighter more hand rubbed style finish, more like a french polish type style.
I've only played them in the noisey NAMM environment, but the ones this summer sounded pretty dang good. They are much more of a "small classical guitar" type of sound, rather than a folk instrument sound. I sort of classify ukuleles like this in my mind. Some builds are more modern and refined sounding, others are more folky and organic. I don't think one is better than the other, just depends on what you like to hear.
The Cordoba 30 series definatley falls into the more modern build category, but I liked the feel and the sounds where solid. The ones on display at the summer show seemed to be better across the board than the winter ones. Not that they were bad, but less consistent from instrument to instrument. Also, it was supper loud at the winter show.
Not too many companies really operate in this mid-price range, kinda half way between the common mass produced lines and custom hand built stuff. I think that its cool that cordoba is going for it in that way. I'm sure there are some growing pains associated with a brand new series, but Cordoba seems really on it as far as putting out consistently good products in the uke market.
The 30 series has a lot of the nuance and style you would expect from an upper level instrument. They seem to be a little lighter build, and pretty vibrant and reactive as a result. My understanding is that there is a specialty shop within the factory that is handling the 30 series to ensure the QC and sound quality is what it should be. I haven't yet handled them in an environment that really favored analysis, but my initial impression was good.