I *hate* the stock Kamaka strings. I've tried Aquilas, Worths, Fremont Hards, and finally have settled on Martin M600 fluorocarbons as my favorite strings for my Kamakas.
I can't comment on any of the other brands except for Koaloha, which I like in terms of sound and playability as much as I like Kamakas, but frankly, they don't appeal to me aesthetically. I don't care for the headstock and I feel that between the headstock, the tuners, and the bridge, there is way too much brand labeling going on. That aside, they sound wonderful and play beautifully.
But I'm a diehard Kamaka girl. And as such, I do have one suggestion for you - I'm assuming you're considering buying new. In that case, I'd recommend passing on the HF-1 and getting the pineapple HP-1 instead. I think both are the same price (they were when I bought mine, but that was before Kamaka's recent price hike) but in my opinion the pineapple is a far better sounding instrument. Louder, fuller, brighter, just all-around better.