When you are looking to purchase phones for your business, you have to ask yourself one question first: Can I accept being locked into a single equipment manufacturer for the next 5-10 years? If the answer is ‘no’, then you need to ensure that the phones you purchase are standards-compliant.
In the past, the model of telephone you chose was dependent on the model of PBX you were installing. Even within a single manufacturer, phones from one system often would not work with a different system. What that meant was that if you needed to change out your phone system, you had to throw all your phones away.
The cost of telephone sets represents a large part of the costs of a new system. If you purchase standards-compliant sets (SIP telephones that are certified by the manufacturer to work with many different types of telephone systems), you allow yourself to migrate to a new system if the business requires that, without having to invest in new phones.
These days, there are all sorts of models of SIP telephones that can be expected to work with most VoIP systems. Cisco (nee Linksys) offers their excellent SPA phones; Aastra provides a fantastic API for customizing features; Polycom enjoys an excellent reputation; and Grandstream continues to provide excellent bang for the buck.
If you really can’t decide, purchase one of each type you’re interested in and test them out. That’s something you can’t do with a proprietary telephone!
In the past, the PBX manufacturers owned the handset market. Today, it is the customer who has the power to decide what phones to use. This competition has driven down prices, without sacrificing quality or features.