I had a Fishman Ellipse system in my Martin XC1T - hybrid mic & piezo. It wasn't particularly reliable, so eventually I took it out and had it replaced with a Baggs iBeam. Very simple, powerful and reliable and gives a very "acoustic" sound - or as much as these things can.

No holes cut. The jack socket is in the end strap button, and the volume control is a disc that protrudes slightly under the soundhole.