It's time to give in ...

I have an OS OU5 and a Kala KA-TE and totally enjoy both of them

I want another concert, but one that is bright and loud, with an unmistakably "Ukulele" sound. Where no one would say," is that a uke I hear?" but rather "hey, that's a uke I hear!"

And it needs to be pretty.

And I'm trying to not go over $300.

Any suggestions?

I'll get things started by suggesting a Mainland Red Ceder. Nice bright tone. More distinct than the Mahoganay. I have 2 Mahogs and they are very "mellow" in comparison to the Ceder. Check out some vids on YT

You may also want to check out the flukes. VERY distinct sound and SUPER durable. Great on-the-go uke, yet a very well built instrument. Not a classic beater.

I personally don't associate "bright" with "ukulele" ...
How about a louder mahogany?