I'm one of the biggest Kamaka fangirls out there, but will be the first to say that they come out of the factory pretty inconsistently. However, in my somewhat limited experience with Collings, I could say the same. I've heard one Collings that is amazing; when I was most recently uke shopping, none of the ones available for sale came close to it - so, I think inconsistency is a factory-uke problem in general. As for the new Martins - again, limited experience, but I've been really unimpressed.
Kamaka ukuleles, Martin strings. Just keeping things simple.