Anyone can help on it, I want to purchase a IP phone from cisco. However, after awhile I ask myself why I need a hardware phone.
What is the benefits? I can not get the answer, maybe the only answer let me comfort is the sip phone no need so much power and no need boot can use by picked up immediately. I tried a hard sip phone of D-LINK of our company the quality is no different of the voice quality with my soft client like ekiga or sipdroid.
Depends how you are going to use the PC as a phone. Few people can use the built in mic and speakers either due to disturbing others or because the mic picks up much more than it should. So you end up buying a headset , many of the bluetooth headsets cost as much as low end VoIP phones. So there is not a big cost savings.
The main reason you want a hard phone is you must be very careful what you are running on your PC when you are using a soft phone. It always seems to happen that the browser eats the CPU or a random virus file scan happens when you are on a important phone call. Although you can tune the machine to favor the soft phone client it only goes so far.