I have never been satisfied with the levels I get out of my instruments. I find that I always have the level on the pickup dimed, then when I turn up the Apogee audio interface I get an unhappy amount of background through the mic’d instrument. I always find ways to tweak things and make it work, but it does make me wonder about switching from an audio interface designed for guitars to an interface that simply has an input. Part of the reason I built the compressor pedal was to get a little more punchy sustained signal, and it worked really well. I almost built a clean boost pedal also. If I were to build another guitar I would probably put electric pickups in instead, in order to get a grittier, more full sound out of my pedal chain. All in all though putting acoustic pickups through a fuzz circuit does create a unique sound.
Yeah, so there must be a major difference between the world of interfaces that sell on the basis of their preamps and an interface that is built to deal with control voltages.