Yup.
I had (and still have!) a good one, my Pono (Whatever, it may not have been that expensive, but multiple people who know ukuleles have confirmed MINE is a good one!) and it has kept me from buying a K brand for a long time because I cannot justify the additional expense (besides not really being able to afford the additional expense). Over the last 10 years of ownership I have played many sublime ukuleles - DeVines, MBs, Beau, LFdM, Hive, Lichty, Ko`olau, you name it - and YES I can totally tell the difference, not only in sound, but feel, playability, everything.
But you know what? It was not until I actually took home my CR and played it A LOT that I see that it is better than my Pono.
Just casually sampling them I don't think is sufficient to determine the differences.
There have been many nice ukuleles I have only played for 1-2 minutes - sure, they sound great, feel nice, etc. but you just can't get all the little nuances of an instrument in 1-2 minutes of playing.
But you sure can tell the difference between a Lanikai and a MB in 1-2 minutes!
I think the most noticeable difference is resonance/sustain/overtones.
You hit an arpeggio on a fine ukulele and hear each note cleanly, but also hear the tone ring a long time, and hear all tones together. That does not happen on a Dolphin, sorry.
I still think my favourite example of this was at an Ukulele Guild of Hawaii meeting when Shawn Yacavone brought in an old Martin - a 1930's era soprano. He was saying how they were like five bucks back in the day. That little thing just had so much voice in it. I normally don't enjoy playing sopranos that much but this one was such a treat to play. Really a neat experience.
I mean, you pick up a DeVine or a MB and you already know/expect it to sound great. This was just so unexpected.