Glad to know you had a good experience with the OBi IP phone and EHS cable with your headset.
I have two 1022s and a 1032, and I agree; Obihai did a great job engineering the audio components in their phones.
If you make a call between two OBi phones with a service provider that supports wideband audio CODECs, the sound quality is amazing. You'll see a "HD" icon on the LCD screen when the WB CODEC is in use.