I am impressed with the UI and ease of use. It's almost perfect.I have only encountered two problems.1) If you select the default auto attendant from the settings menu (default 'Call Me' ) it does not work correctly. Instead of pressing 1 to answer the call, the system hangs. You have to press 0 and it will work.2) Sometimes when making calls the application crashes without warning. This happens especially if you make many calls in a row. Usually after about 20 calls. In those cases you have to reboot the computer. For me it happened after 100 calls. I'm sure this could be improved but it's a great tool.