Hi Marcus,
The replacement(s) for the CS55's is the new CS500 series. We just got our
first CS540 and it's really great. I can't tell you how it works long term, but it
does look like a very nice product. If you are using these with your 7962's you
can also order the APC-40 adaptor which replaces the need for the "lifter" kit
and allows you to leverage the Headset Hookswitch Control (HHC) setting on
the new phone models to answer and disconnect calls from the headset itself
without pushing any button on the IP phone
http://www.plantronics.com/us/media/media-resources/literature/office_callcenter/cs500_productsheet_en.pdf?WT.dl=20
Cheers!
Rob
PS: the CS510 and CS520 look pretty heavy duty but not quite as appealing to the eye.