I recommend the Panasonic DECT 6.0 phones. I switched from Vtech and I'll only buy Panasonic from now on.

I do tons of conference calls from my home office and the Panasonic DECT 6.0 phones are the best phones I've ever used.

Here's why:

1) voice clarity on the wireless headsets is as good as a landline.
2) Uses AAA batteries, so easily replace the rechargeable nimh AAA's when they start to wear out.
3) Has headset plug to use any standard 2.5mm headset
4) great mute function
5) the speaker phone function on the handset works perfectly. People cannot tell if I'm on speakerphone or headset or talking directly into the handset.

Aside from that it has a ton of other features. You can't go wrong with the Panasonic DECT 6.0 phones.