Yes- I think I’ve tried most all of them including K&K. To me they all sound good, but the Dazzo’s add that extra 10%. All pickups for acoustic guitars are a compromise compared to a good mic, but the Dazzo’s are pretty good if you’re looking to add a system to a guitar. They’re also passive, so no battery required. They work good alone, but paired with a good preamp (Sunnaudio is recommended) it’s golden. The Tonedexter or Grace Design Felix pedal also is highly praised for use with most any piezo.
With that said, I lead worship every week using an acoustic guitar (Martin GPCPA-1) equipped with Martin’s Thinline Gold under saddle piezo paired with on-board Fishman Aura preamp. This is the best plugged in sound I have ever had, but I don’t think this system is available separately (the pickup is but not the preamp) for installation into any guitar.