this modem be purchase to replace a ancient lease modem from Comcast -lrb- Surfboard series -rrb- that be start to randomly drop the link . the modem be select base on rating on Amazon -lrb- and elsewhere -rrb- and the fact that it be one of the few three-star modem indicate as fully compatible by Comcast . the only real issue in install it be to get through to Comcast support to give they the modem type , serial number and MAC address . after the wait for someone to pick up my request for action in install my own modem thing go pretty smoothly . pro : before install the sb16121 the download speed with the old Surfboard modem be 14-16mbps and upload speed 1.4 mbp to 1.6 mbp . after install the new new DOCSIS 3.0 certify modem the speed increase to 25mbp + download and 5-6mbp upload - very nice ! the front panel indicator can easily be see and give a good indication of the status of the connection with the isp . the ac adapter be easy to plug into almost any surge protector or up -lrb- it be not as likely to block nearby receptacle for example -rrb- and the supply network cable be of good quality . documentation be spare but to-the-point and informative . con : the only flaw -lrb- and it be a modest one -rrb- that I have note so far with the modem be that it be easily tip over . since the sb16121 vent heat to the side you do not want to block the flow of air by place book or the like to keep it upright since they could cause excessive heat build-up and a potentially shorter life span for what be not a cheap product . so far the solution have be to prop it up between a low-profile Linksys wireless router this computer use and a small -lrb- less than 2 '' high -rrb- usb hub . this all might be no big deal to those of you with deft and sure hand and motion but I be willing to wager a nic or two that I be not the only goofily-coordinated nerd out there and the sound of this modem smack down on its ' side every 15 minute or so be disconcerting , and possibly a threat to the warranty . a recommend product for those of you whom want to own you cable modem instead of lease it from you isp and\/or want to upgrade performance .