Does anyone have direct experience with Aastra, Polycom, or Grandstream phones?
This was selected as Best Answer Aastra & Polycom are both excellent. Grandstream awful – cheap and poor quality. I have no personal experience with Snom but they seem to get universally good reviews from their users. For our own use we use Aastra 9133i [support broad feature range and up to 6 lines] and our staff raves over them [having converted from Avaya 4612 series phones from the prior PBX]. If you are thinking of high volume usage on the devices [such as call center agents etc], it is far more popular/effective/efficient is to use a Plantronics USB headset in conjunction with a softphone [for best results, get a multiprotocol softphone so you can use IAX connections rather than SIP]. You might want to check the www.trixbox.org forums where there are extensive threads about end point devices as well as specific forums moderated by the endpoint device manufacturers.