I don't know if it is officially a controversy or not but there is enough communication traffic about which pickups to buy on the web to make you want to stick your head in the sand and hope it all just goes away.
Being a praise and worship leader at our church and gigging with a friend of mine, I have no choice but to amplify my acoustic guitar and there are three or four possible ways I can do this:
1. Mic the guitar with a condenser or dynamic mic mounted on a mic stand.
2. Use a magnetic pickup mounted in the sound hole.
3. Use a piezo pickup mounted under the saddle or under the bridge or both.
4. Any combination of the above.
Ok, so what is the problem? Just pick from the above until you find the right sound or tone you would like to achieve. What can be simpler? Well because some of these solutions are ideal but may not fit into the budget of a weekend guitar player. If money was not an object I would most likely have gone with a system such as the Seymour Duncan SA-6 with an integrated mic. In the end I have decided to buy a piezo pickup system from Barcus-Berry, but let me share how I arrived at this decision.
The Condenser or Dynamic Microphone - This is the traditional approach and is the best approach for natural sound reinforcement, but it has several key drawbacks for me.
Drawback #1: Using microphones generally mean that you are stuck sitting or standing in one spot and although this is many times not a problem, I like to be free to move when possible. Also I tend to feel a bit crowded by all the clutter and the microphone's proximity to my guitar. Product Example: Shure 58
Drawback #2: Too many cables and stands make for more stage clutter. On small church stages too many cables makes for not only a danger to people who approach the stage to speak but also make it difficult for the musicians to maneuver.
Drawback #3: Feedback. Although controllable it does require a good sound tech and/or feedback suppression systems.
Magnetic Coil Pickups - Inexpensive, quick and easy to use, these pickups mount into the sound hole of any acoustic guitar. Example: Seymour Duncan Woody
Drawback #1: The sound is completely synthetic and is based on the vibration of steel strings over the coil. This is how electric guitars are generally amplified. Spending money on a really good acoustic will not be heard using one of these pickups. It does in my testing sound better when strumming and not picking individual notes.
Piezo Pickups - These are a good compromise when looking for a pickup which better simulates the sounds your guitar creates. Basically they take the vibrations created from the saddle/bridge area of your guitar and translate them into sound. Here there is no mess with too many cables and microphone stands. Many professional guitarists use this pickup in conjunction with a microphone. This approach is called a blended approach. Product Example: Barcus-Berry Insider
Drawback #1 - Still a synthetic sound but doesn't suffer from completely sounding like an electric guitar.
Drawback #2 - Harder to install than your typical sound hole mic.
Blended System - Blended systems are usually a combination of microphone and piezo pickups. This is the best of both worlds and is becoming very popular. Product Example: Fishman Rare Earth Blend
Drawback #1 - The price. Systems like this run in the hundreds of dollars.
Drawback #2 - Usually more complicated to install and may require a luthier's help
Well that is how I arrived at the modestly priced Barcus-Berry piezo pickup. In the end it was all about the money and how to achieve the best sound for under eighty dollars.