Under saddle transducers irritate me. I don't care for the amplified tone (that notorious quack) or what they do to the acoustic tone.

I like the K&K products in several of my instruments. They're the best of all worlds for me...no battery, no affect on acoustic tone, simple to install, reasonably affordable, decent tone...

Over the years, to overcome a feedback issues and to accommodate electronic multi-fx, I experimented with soundhole pickups and rejected the first few I tried. Then after a few years I discovered the Fishman Rare Earth. I have them in the Weissenborn copy, a Simon & Patrick all mahogany folk, and a Beneteau flattop. I just got a used LR Baggs that I installed in a House folk. I can't believe how good they can be made to sound, not fully acoustic of course, but not at all unpleasant, very easy to control, and easy to mix in a band context.

The first Fishman style soundhole pickup I saw was actually the precursor made by someone else who supposed sold or licensed or whatever the idea to Fishman. If I'm not mistaken it was English in origin.