Unfortunately I live in an area that doesn't have much ukuleles to try or buy. All local stores carry only laminate ones and if lucky some all solid tops and Martin CK1:s. My friends don't play ukulele and consider me gone completely nuts with this uke thing of mine. So if I wan't to try new ones, I have to purchase one. It is very important to me that my instrument is all solid wood (my bank account says a huge thank you...). And I'm fascinated with the Hawaiian koa ukes. I love the sound! On top of that I'm a very curious person, I wan't to play different well made ukuleles even though I'm really not worthy. It just brings enormous joy to hold and play a beautifully made masterpiece. Is it reasonable? Nope, I could surely learn to play an ukulele with way cheaper one. But it is so much fun!
I'm fascinated by the history of the Kamaka ukuleles. And I would like to experience the famous 'KoAloha sound'. If I'd had the money and the opportunity, I would buy both in a heart beat. But it doesn't stop there! Lately I have been more and more interested of Kiwayas, ANuenues and Oulcrafts... a slippery road indeed.
Early on I thought that the concert is the size for me. But after hearing some videos by Samantha Muir I started questioning my choice.
If you are in Europe, you might have better access to a number of UK builders (including ones who've built for Sam Muir). There's another thread right now discussing sopranos and UK luthiers. It seems like they generally lean more towards the Martin sound than Hawaiian. If your stores carry CK1s, maybe they have Martin S1 sopranos as well? Those
might give you an idea of what to expect from UK built sopranos, although I think the S1 is a really great ukulele itself.
As for Hawaiian, KoAlohas are my favorite, and are particularly great sounding in soprano and concert sizes.
Despite their rich history, modern Kamakas seem to be even better than their vintage versions, and for me, none of their sizes stand out as better than another. I like both concerts and sopranos, and for Kamakas, that looks like a contest between the concert's sail headstock and the traditional heritage of their standard. And their pineapple shape, which they invented.
Like you, I've recently turned my attention to Asian builders as well, who've been producing some amazing instruments, though most of my focus has been on Japanese makers who aren't as well known.
One possibility for you, if it's feasible, is just buying and selling ukes to experience as many as possible and help you find what you want. A lot of UU members have done just that, and just deem any losses as the cost of trying out lots of ukes. That cost can be minimized by buying second-hand ukes.