Summary: I guess I didn't know what I was missing until I installed the Polk speakers. The sound is top shelf! I use them as surround speakers and they are set to dipole. The challenge now is to get a receiver that can push these speakers to operate optimally in your environment. I had to return a Denon 105 watt per channel receiver because the amp could not push the Polk's, nor the Bang and Olufson fronts. The amp would heat up and shut down at 60% volume.
Summary: They seem to be great. Handle surround perfectly. Easy to mount and versatile. If I had a negative it would be the ability to reproduce music at higher volumes. They act "small" and the A6's might do a better job. However still very pleased for what I ask them to do.
Summary: The speakers are a decent size. I was watching a moving and i will admit i got scared. The sound that these speakers produce is impressive. It caught me off guard and made me jump. They integrate well with the rest of my polk speakers. This is a good buy.
Pros: Price, sound, easy to mount
Cons: I wish it had another driver on the other side.
Summary: I purchased these as refurbished speakers from the polk direct ebay store and have not yet had the opportunity to hear them in a surround sound environment due to the right one arriving with a blown woofer. I gave the FXI A4 speakers 4 stars right off the bat for two reasons, I have high expectations, and I didn't want to artificially bring down the reviews from people that have heard these while they are working.