I always thought acoustic guitars sound bad live and there's little to do about it, until I discovered LR Baggs. I use this mic/piezo combo system on 3 acoustic guitars (a Cort dreadnought, a Norman 12 string, and a small craft-made old guitar), and I looooooove the sound and I've never encountered any problem.
If you're looking for something that makes your guitar amplified sound close to its actual sound, then the Anthem is what you want.
note: I used to play with Fishman and Shadow piezo pickups before...now they belong to the bin. If only I had tried LR Baggs before, I would have saved lots of money and been more relaxed onstage.