I think this is a tough one, because it's different for different people. For some folks, it's love at first sight. For others, it's "let's get to know each other." I do know that for my favorite instruments, they became my favorites because I spent some serious time with them and learned what it took to get the best sound of of them.
When I first got serious about uke last year, I fell in love with Peter Lieberman's Maui Music design, and wanted one bad. I finally ordered a long-neck concert from Gryphon in Palo Alto. When it arrived, it sure was beautiful, but when I played it, I went "eh". It was a good uke, but it wasn't the mind blowing experience I wanted it to be. Was that the fault of the uke, or the fault of me, for expecting the instrument to change my life? Or simply because as a relatively new uker (but longtime fretted instrument player), I simply didn't know how to get the best sound out of uke? We'll never know, because I sent it back to Gryphon (where it sold, instantly). A few months ago, I bought a similar Maui Music tenor here on UU. It's a lifetime instrument-- hands down, the best traditional tenor I've played. Is it a better instrument than the first one? Do I like the Tenor tone better than the Concert tone? Have I been playing long enough that I understand uke tone better? I honestly don't know-- I just know it's a killer instrument.
I guess my final though on the subject is: life's too short to play an instrument that doesn't give you pleasure. And speaking as a very satisfied Mya-Moe player, the Mya-Moe that ain't working for you may be a lifetime uke for someone else. My guess is that if you put a Mya-Moe on the UU Marketplace, it will vaporize on contact, so you'd be able to get the money to finance something that makes you happier. If I hadn't just received my Koa Mya-Moe, I'd probably be first in line to take it off your hands!