After many years with the original Toshiba PCX1100 rented from the cable company, I decided to buy one of these units, hoping that I might start to see some change in my connection speed as hyped by Comcast's "Power Boost" marketing. When I ran internet speed tests I consistently got download speeds from 4-6 mbps, when Comcast said that PowerBoost now gave me up to 12. Upload speeds were pathetic - under 100 kbps! Just as others have said, once I plugged this in and registered it with Comcast, I started getting speeds over 16 mbps - three to four times as fast as I had been with the old modem. Upload speed is now faster than download speed had been. The Comcast folks chuckled when I brought in the old modem - "I haven't seen one of these in forever!" Buy this - you won't regret it!