User interface is chuck full of charge-up bombs! Oomas "FREE" service starts out at $60 per year and one wrong click on the user interface and WHAM*!#% $200/ year (starting point) for the same services you were getting for free....Oops I mean $60. Two wrong clicks could land you above $400/ year on their "FREE" phone.
I called customer service on the day they charge me for an unknown "click" (caller block feature), (had 17 old blocks not charged. Customer service said, "you click we charge and will not reverse charges".
Ooma's unforgiving data handshake with their server send a VERY ANNOYING "beep" (like your being recorded)to the ones at the other end of the conversation. This "beep" comes from the server getting lost and needing to be re-synced with your equipment.
As a side comment on Ooma's claimed "#1 VIOP service" with only 600,000 customers falls far short of MagicJack's near 3,000,000 and charging less than $40/ year for the same service (more if 911 service). Plus MagicJack's App on your cellphone to receive and make WiFi or data calls explains why Ooma tanked on their stock offering to the public (IPO).