While firmware optimizes the signal, physical factors remain vital. Using a direct motherboard USB port (rather than a hub) can eliminate interference, while performing a hard reset through the device’s physical buttons can clear the spatial processing chip's cache after a major update. Conclusion
Because Plantronics (Poly) has merged with HP, official support for the legacy P610 has ended. The "Extra Quality" files are now abandonware, but they are preserved in communities such as: plantronics p610 firmware extra quality