First lets get the facts straight. Both are needed and can be used on all types of platforms. for those interested in voice over IP visit our VOIPiT forum where we discuss Voice over IP software and hardware reviews.
Software based phones:
Pros: Free or low cost
IP USB phone compatible ( phone set) $29
Con: Have to own computer and be able to install software and manage applications.
Slight learning curve for those new to the net.
Hardware based phones
Not all vendors are the same. tested several items, and they just did not make the cut. They lacked in either echo cancellation or feedback controls. A decent phone for the dollar is our Roby Ip phones found online here.
I love my Sipura 1000, and 2000, and looking for low end unit that meets quality controls and service.