I use the Rare Earth Blender (magnetic humbucking pickup with an internal condenser mic on a small gooseneck which comes off the bottom of the pickup housing, inside the guitar) in both of my principal acoustic guitars. But Jed makes a good point about whether the on-board blender system is really all it could be. I tend to use about 75% pickup and 25% mic under ideal circumstances, but if I'm on a loud stage I often find that I have to dial out the mic altogether, and just use the pickup signal. Even with the ideal 75/25 split, the microphone is not all it could be, largely because of where it is -- inside the guitar body. Jed's approach of using the Rare Earth pickup-only model in conjunction with a mic on a stand is likely to produce a better sound. The only drawback is that this forces you to stand still -- which some of us have a problem with. But if you can handle it, it might be a good way to go. It also allows you, as he said, to lean into the mic a little more when you want to add emphasis.

Another option, which I have not tried, is the latest generation of Rare Earth Blenders. These actually have the microphone on a detachable gooseneck suspended above the strings, not inside the body of the guitar. Anyone have any experience with these?