Another vote for Kala. I have a Kala baritone and love it. I also have a Mainland concert uke, but am not nearly as happy with its intonation or action, and would not buy another uke from them.

The damn little concert uke keeps slipping out of my grasp: another reason I'm happier with the baritone, which is fitted with a strap. I've tried fashioning a makeshift neckstrap holder, but it doesn't seem to help appreciably.