I have one of the solid acacia tenors that I just got for Christmas.
When I first played it, it was not as loud as I expected, but I wasn't playing it very agressively. When I played a song where I was strumming harder it had a lot more volume. To me it sounds great.
The intonation on it seems pretty spot on.
As far as looks go, absolutely beautiful.
It feels different than the other ukes I have played. I haven't played as many ukes as a lot of people on here, so others may confirm that most new ukes feel like this Kala, but I'll explain the feel anyway.
I've played an old Kent soprano, an old Beltone baritone, a cheap touristy soprano, and an Oscar Schmidt OU53-S baritone.
The Kala solid acacia feels much softer than all of the other ukes. What I mean is that if you take the string off and just rub your palm across the ukes body it feels like there aren't any imperfections and everything is smooth and it just feels nice. I thought it might have just been in my head, since this is my very first uke of my own. But then my wife mentioned how much softer it felt than the Beltone and the Oscar Schmidt and she doesn't play.
The current knock is some people have been reporting that the saddle on their solid acacia Kalas are a little loose. I haven't changed my strings yet, so I can't really say that about mine one way or the other.
My personal opinion is that the uke is beautiful, the intonation is on, it sounds great, and the feel is incredible. Did I mention how nice it feels?
Anyway, I would recommend the tenor and I don't see why the concert would be much different other than maybe not quite as much volume due to body size.
I say it's worth the money.