I have used Nextiva for my business for about 3 years. While their features, call quality and reliability are all very good, what really sets them apart is the customer support. I have access to the control panel and can make any changes from there, which is nice. I can also use the iPhone app for updates. This is very convenient since I don't always travel with my computer. Even better is that when I need help, I can call Nextiva customer service and they always help me.