We prepared the following blog in October 2017 with some options:
Your Customer Success Team members have tried out and use/used the following headsets:
Plantronics Vista M22 which is a wired headset w/2 ear covers. This is connected to the back of a hard phone w/headset option. Not compatible w/MAC or PC.
Logitech ClearChat Comfort USB Headset Wired Connectivity - Over-the-head (wired USB headset - requires OnSIP App as your registered device. Also nice earpiece and mic. Very clear sound/call quality. Personally, b/c I like to walk-n-talk the wire is a nuisance.
Logitech H390 USB Wired PC Headset for Internet Calls and Music. Lightweight and a longer cord.
Sennheiser DW Pro2, DW 30-US, DECT. It's a wireless DECT headset that uses either a direct connection to the back of a desk phone OR USB connection to the computer using the computer to answer your calls (you'd need OnSIP App [web or desktop] enabled as the softphone on your computer). Nice headset, sound-canceling, really sleek, nice mic, no reported issues w/audio inbound or outbound.
Jabra Evolve75 headsets are the latest testing headsets. Wireless and very nice. At least 25' before starts to lose call quality:
YouTube video of the headset and use in an "open mic" test:
Polycom website has the following information about headsets as well (as of January 2016):