I have lights on my vintage Kamaka concert and they are very nice. Lights may play a touch easier on a concert, but if you like a fatter string feel mediums are also fine, I have them on a tenor. I think the fatter medium string will give you a slightly higher tension on both sizes, so how much tension do you prefer? It however might not even be that noticeable to you, but could have a very slight effect on tone. One of each, you get two sets so you can try light on one and medium on the othe uke, then swap next time around. I feel both play easy and sound great on their respective instruments. Both are koa but sound different. The Kamaka is brighter. I think the Pono tenor because of the thicker finish might sound better in clear mediums. It sucked with Aquilas BTW; hard tension and unpleasant feel and tone. The Worths are softer, easier to fret, cleaner sounding (to me on that tenor) and nicely mellow, whichever you choose. Lights are on the Kamaka solely because of a belly issue.
