Got these (lights 12-54) for my Taylor GS Mini. I was initially concerned about the gauge being too light/heavy as acoustic string gauge seems to vary from one manufactor to the next but they sound and feel perfect for me once strung on the guitar - loud, rich, balanced and not too bright.
I've previously always used Ernie Ball Earthwood PBs on my acoustics but needed something a little heavier as the neck on the guitar is a shorter scale and these strings had come recommended from various Gs mini owners- I'm not disappointed either, the tone seems enhanced and they deliver ease of playability too, not hard on the fingers at all, the guitar seemed to come to life.
Can't comment on the lifespan at this point sorry, will keep posted.
Would recommend you give these a go if in any doubt.