I have a K&K Pure Mini in my TV Southerner Jumbo, and I play it through a Fishman Loudbox. I like it a lot, and it does not sound 'quacky' at all. Sounds better than the Fishman Matrix Infinity under saddle I used to have. And, it sounds better than the Fishman Neo (sound-hole magnetic unit). I like the fact that it is passive, and does not have any added electronics/battery in the guitar. Signal is plenty strong for the Loudbox preamps to handle. I don't gig so there is no feedback issues at all. I went with the vintage style end-jack that takes 1/8" plugs. Weird size, but it works for me and keeps a nice "un-modded" look to the TV.
If I do another high-end Gibson, I'll go with another K&K Pure Mini.