I helped a friend install a K&K Mini pickup system in his acoustic guitar with the assistance of Rob DiStefano's pictorial guide. The install went without incident. We installed all 3 mics at once like Rob shows.
http://frettech.com/kk/
I would say that the pickup sounds like I expected. Overall, it's really a nice sounding system. The highs need a little boost, as you might expect from a mic system under the top and the level is lower than a typical piezo system.
I'm looking forward to hearing it tomorrow through the PA. Judging from the palying we did through my PA, it's a deeper sound than his Taylor and I may be scrambling to change my pickup & amp settings to fit in the mix with him now.