A little late here but…
I have never been satisfied with the sound of a piezo pickup for acoustic instruments. To me they always sound quacky and electronic.
So that said, here is a little extra expense but I found that it really changes the sound of a piezo pickup. I have Fishman Aura pedals. The current model, the Fishman Aura Spectrum is really expensive so forget about that unless you have suddenly increased your budget.
But before, Fishman made Aura pedals with names like Dreadnought, Acoustic, Concert… These models were keyed to specific types of acoustic guitars BUT hidden inside was software that could make the pedal very flexible.
The Aura operates using ‘images’ but let’s say for convenience’s sake that they are models (they are supposed to be much more sophisticated and magic than just mere models). So there is a huge library of models available including the Blueridge BR 140, 143, 160 and 163. The idea is that you match your own guitar with one of these images (so say, a Blueridge BR 140 recorded with a Neumann M147) and then the image matches and blends in with your original sound.
What it does is make the nasal, quacky piezo sound more woody and stringy and, basically, more acoustic. There are hundreds of images so you mix and match. I have a Taylor 310 and I use Taylor 800 images for a match.
Anyway, if you buy one of the older pedals (but not the oldest ones, you have to buy the ones with guitar ‘type’ names) you can then purchase a software update from Fishman that will allow you to use any of the images in the library (there’s even dobro and violin images).
You can find these older Aura pedals on Ebay for well under $100 if you’re patient (not everyone is aware they are updatable. The USB plug is ‘hidden’ under the metal plate with the serial number). The update costs $30. You just need the downloadable update. The more expensive option with the CD ROM really isn’t worth it.
Anyway, if you find that the sound of the Baggs is a little unnatural sounding to your ears, don’t despair. It will cost you maybe $100 for the Aura plus update but it will be worth it.
Here is soundclip I did:
https://www.soundclick.com/html5/v4/player.cfm?songID=11928488
Even more astounding, not for the playing but for the acoustic quality of the sound, is this. This is a solid body nylon string guitar and a semi-acoustic fretless electric bass, both using the Aura:
https://www.soundclick.com/html5/v4/player.cfm?songID=11938314