I am not on a quest for the perfect strings, but I change my strings every 2 months. In the process, I've tried a several lines of string on my Kanile'a Super Concert.
I love my Kanile'a for its warm, reedy tone that borders on dark. The Super Concert does beautiful things with the 1st and 2nd partials, so I prefer strings with strong fundamentals and lower partials with just a pinch of upper harmonics.
I have oscillated between Aquila and D’addario. Here are my impressions:
Aquila Nylgut - Stock strings. Warm, powerful, and widely available. Beatiful when fingerpicked with a shaped and polished fingernail. I usually use either these or D'addario Nyltechs.
D'addario Nyltech - I frequently use these. Less paper-like the touch than Aquila Nylguts but otherwise very similar.
D'addario J71/EJ65T - Classical guitar strings repackaged for the uke. High-tension strings with warmth and sustain. Excellent for strumming or rocking the melody between the A and re-entrant G strings. Good for addressing technical flaws. Great all-rounders but too guitaresque for my tastes.
Living Waters – my one foray into fluorocarbon on the Kanile'a. Good balance between strumming and picking. I miss the warmth of nylons whenever I use them, but I keep a few sets on hand for when I want the tonal change. Great choice if you’re seeking that "ukulele" sound from your Kanile'a, want a brighter tone, or want good all-rounders without the tension of the J71/EJ65Ts.
In short, I favor the Aquila Nylguts and D'addario Nyltechs, but I'm not seeking the typical "ukulele" sound. I have a Koaloha soprano strung with Worths for that.