After a great deal of research for my circumstances, this specific cable modem is my best available option as a "supported device" with Comcast, my Internet Service Provider (ISP).

Amazon Prime offered a competitive price (since increased). The order arrived on time along with another Amazon order placed later that arrived a day early.

If you are a basic internet service consumer, you probably are not shopping for a DOCSIS 3.0 cable modem. If you want the best "bang for your buck" and need fast internet access say for video on demand or online gaming, read on.

Bottom line, this Cisco DPC3800-CC cable modem works on my Comcast service. It does not operate at DOCSIS 3.0 speeds.

My quantifiable thru put is now more than doubled by replacing a leased DOCSIS 2 cable modem with this DOCSIS 3 modem.
The pay back is 12.2 months by eliminating the Comcast modem lease. My disappointment rests with Comcast, not this product. Here is why.

While the FCC wants US ISPs to make 100 million bits per second (100 Mbps) download speed our national standard by 2020, we are FAR from that standard in 2012.

A cable internet provider that implements the full feature set of the cable industry's DOCSIS 3.0 standard could meet the FCC objective. But my service provider is not even close and has no incentive to do so.

All we can do, as consumers footing the bill, is to be informed (search "DOCSIS 3.0") and purchase products that will work if the service level is provided.

You need to understand that there are three variables to your quality of internet service:

1) cooperative manufacturer / service provider relationships to assure proper "provisioning" or the `hand shake' between the hardware and the ISP;

2) an ISP willing to implement a supportive infrastructure; and

3) the ISP service level and equipment you select to pay for. I chose the Cisco DPC3008-CC to address factors 1 and 3 and understand that Comcast is not now providing adequate service to my location to achieve service levels this cable modem is designed to provide.

In other words, I cannot downgrade the DPC3008 device rating due to my ISP, service factor 2!

I moved from NW FL to SW Florida a few months ago in 2012. With the same hardware (a DOCSIS 2 Scientific Atlanta cable modem), different cable providers (Cox & Comcast) I had 2x faster thru put with Cox cable than I now have with Comcast with the same modem.

A personal visit to Comcast's local service office confirmed yesterday that my location is not receiving the highest speeds Comcast offers here.

In contrast, I received better than advertised thru put from Cox (try 32 Mbps with the same DOCSIS 2 device!).

The installation was simple. The CD based user guides are not clear. Yes, you can just attach the new cable modem to your cable without wasting time to call technical support, assuming your cable internet is operable.

Keep your working cable modem until you set up your new one. As per the user guide, simply connect the new modem and power it up.

Observe the lights to confirm the new modem on your cable initiated your ISP's automatic provisioning. Now, direct connect your computer to the modem, power cycle the modem and open your browser.

You eventually will see a screen that requests your account number and registered phone number, maybe the last 4 digits of your SSNO.

After a reset, I was good to go. The last install step is to then connect your wired / wireless local area network. You can do this within 30 minutes.

After testing that, I drove to Comcast, turned in the leased cable modem and challenged their service level to no avail.

I will edit this review later if I experience any issue specific to the Cisco DPC3008-CC. I conclude that the negative reviews here are from inexperienced users or perhaps a firmware or provisioning issue now corrected by Comcast and Cisco.

After 24 hours, it is still working and never rebooted. If a user does not properly "provision" the new modem with the ISP, it will exhibit the reboot symptom complained about here.

I deduce that the Comcast recommended speed test site (Speedtest.net) is optimized for my local Comcast service since its measured speeds with two different cable modems were nearly twice that of a different site (Speakeasy.net).

Within 24 hours, I ran 4 tests of the two different sites. With Speedtest.net, my download / upload average speeds were 15.4 / 6.2 Mbit/sec with the DOCIS 2 device versus 28.4 /5.3 with the Cisco DOCSIS DPC3800. With Speakeasy.net, the averages were 7.0 / 6.0 before versus 28.4 / 4.0 with the Cisco modem.

Clearly, the Cisco DPC3008 DOCSIS 3 cable modem performed better than a Scientific Atlanta DOCSIS 2 cable modem. Is the expected DOCSIS 3 speed attained? NO. If you read all the above, you understand that I hold Comcast accountable, not this device from Cisco.

Am I obtaining the DOCSIS 3 benefit of 8/4 dynamic channel bonding? There is no way to tell, except my speed test suggest NO. I do not now know if that is hardware or an ISP issue.

Yes I am receiving the DOCSIS 3.0 benefits of IPv6 and a gigabit Ethernet port. Yes, the setup was easy.

I chose the Cisco DPC3008 primarily due to its DOCSIS 3.0 certification and its acceptance as an approved device by Comcast.

Comcast has few DOCSIS 3.0 devices on its approval list that are still marketed by the manufacturer for consumer purchase with the 8 / 4 channel bonding and IPv6 features of DOCSIS 3.

The newer Cisco DPC3010 and newer devices from several manufactures are not yet approved so I stuck with the older DPC3008. Why Comcast seems to need 4 years to certify a device, six years after DOCSIS 3 is defined is unfathomable.

Cisco seems to have gone the extra mile to assure its device is acceptable to Comcast, factor 1 above. This specific cable modem is my best available option today and it works.

9/21/2012: Most recent speed test is 36.2 / 5.2 Mbps. My Netgear wireless router died after only two years so I substituted a Cisco unmanaged switch for trial.

This resulted in frequent outages of the DPC3008. I mention this trial it may be possible that reviewers who complain about disconnects are not direct connecting to the DPC3088 with one device or connecting a router / Ethernet hub to connect multiple devices.

The unmanaged switch is not designed for this. Cisco's "documentation" is not even clear or helpful about how to connect anything but a PC!

With a router or with only a single PC connected, the DPC3008 has been "rock solid" since my initial installation.

I learned that I am not in a prime Comcast area so "Blast" is not available to me yet I had no difficulty installing / provisioning the DPC3008 to replace the rental cable modem.

I regret that the Cisco device does not confirm channel binding status. I therefore cannot tell if my fractional speeds versus advertised speeds are poor signal, bad provisioning by Comcast or simply Comcast throttling the speeds.

Last, a few report poor speeds while many report easy installation with 2 to 3 times the former speed.

Aside from a defective unit, if you are using Comcast and not obtaining reasonable speed, your DPC3008 may not be correctly provisioned (Comcast's handshake with your device).

If you are as inpatient with phone support as I am, it is faster to simply take the DPC3008 and box to Comcast customer service to ensure it is set up for you.