I have used quite a few MOV type surge protectors over the years. ALL of the MOV based surge protectors I've owned have failed.
I also bought an "audiophile" single-outlet power conditioner from a well-known company that makes very expensive power conditioning products. That unit, which was admittedly an "Entry-level," device from its manufacturer, shorted out and smelled bad after approximately two years. ($495 gone.)
I have owned three Brickwall power conditioners for 10 years. I have two 20 amp, 10-outlet units and one 15 amp, 8-outlet unit that is designed for Audio use. I bought these units to protect audio gear that would be very difficult and expensive to replace. The Brickwall surge protectors have been through many storms and other weather-related power "events." They even lived through a hurricane. My Brickwall surge protectors have not failed in any way, and our audio gear is still functioning as intended.
The issue of sound quality is harder to nail down, because power quality varies so dramatically, even from one circuit to another circuit in the same home. What may be an "improvement" in your house can be a "softer" sound in another location.
I am not saying that Brickwall products are more effective and more durable than SurgeX and Zero Surge. I do not have personal experience with those companies. I can only say that Series Mode surge protectors are the most durable and effective surge protection devices I have found in my own limited experience.
I hope this helps.