Plantronics Voyager 5200UC (Open Box)

I have purchased eight of these headsets and used them for over a year before I posted this review. From my testing of eight of the 5200 series, I have concluded the 5200 series has serious issues in quality: Battery life under performance: 7 to 8 hrs use expected (W/O HD Voice) on avg use, expect four+ hours Voice Commands Notifications fail frequently: goes silent, status isn't available or voice commands available, there's a way to reset sensors by holding vol up& down while turning it on. This only works for a while. This is consistent on the eight headsets I have purchased. Charging port: The accessory case (separate purchase and four different ones tested), charging isn't consistent. The USB port on the headset is often difficult to connect; and the rubber dust cover (On USB) will eventually will fail and no longer be attached to headset. The type of power charger used will play a role as the headset will not charge with high wattage power adapters. The interface is an older version of USB, not USB-C requiring more accessories if you travel. (Charging Cases do not work correctly for me) Bluetooth interference: often I find when in a room w/ other Bluetooth devices there's a level of interference which causes frequent disconnects of the headset. If you have more than one of the 5200's paired with a device, and both are on, its not smart enough to know which one you're wearing. This is a simple software fix. (Senor can tell when you are wearing it) Firmware Updates: Keeping headsets up-to-date is very important. I find that poly has limited & restricted manual firmware updates. Some updates should be reverted for better performance. Its pretty much a one shot deal; take what they offer and that's it. A word of caution too: when looking for firmware updates, I discovered their refurbished headsets do not have the same firmware as a new headset. Performance and feature rich options appear to be more limited/restricted. Microphones drop: I've noticed at times when the battery life is below 25% that the microphones become intermittent. People in conversations complain they cant hear me, so I change to another fully charged 5200. I attribute to poor design and poorly written software. This could be fixed w/ software by notifying the user to charge the headset. Comparing the older models of Voyager series headsets, the older out perform the 5200 in every aspect. After they company was bought out, the quality went out the door with it. I expected the same operational performance as the older voyager headsets and I was wrong to assume that Poly would continue the same quality in the 5200's. 5200's have caused me a great deal of frustration in day to day business. I'm now searching for a different brand all to together. I implore that you take pause before purchasing a Poly 5200 headset; research is your best defense to determine a Bluetooth headset product which best suit your needs.