Customer Ratings & Reviews

This Motorola MB6721 was easy to set up, although it took Xfinity 15 to 20 minutes to recognize it. I have this modem (with an added WiFi router) for just over one month, I have not had any problem with it. It saves me $14 a month of rental fee. I recommend this to any Xfinity cable internet user who is renting the modem from Xfinity with internet speed no more than 600 Mbps.

Easy to use, better value than the Xfinity options, lightweight and potent. This unit is a great deal, seeing how it’s been listed for over $100 in other places.

After a bad experience with a Netgear cable modem, I decided to buy this Motorola model. The purchase was based on reviews I read online. I have had no problems of any kind with it. I’m pleased with the modem. I am using it with a Linksys router model EA7200.

I needed to change the cable modem by switching to a faster internet plan. The previous product sometimes had to be rebooted due to unstable connection, but this Motorola product does not need to. It is very stable and has excellent price-performance.

Not a good Modem. Had slow connection and internet outages. Also realized that it was not able to handle my service speed and features.

Solid product. I bought this because I was upgrading our internet speed and our old modem was over 5 years old and didn't have the channels needed to maximize the faster speeds so this was just what we needed and it's worked flawlessly. I would highly recommend everyone buy your own modem and router and save some money every month by not renting the equipment from a cable company. They pay for themselves pretty fast.

We are very please with this modem. It is reliable, fast, and has a small footprint. Highly recommend. We had to replace a Netgear modem/router combo that was only a year old but kept dropping the internet connection. Even Netgear support could not correct the problem. Disappointing for the cost and age of that piece of equipment. We have only been using this for about a month but could not be more pleased. It runs much cooler than the Netgear.

Replaced an older Motorola 3.0 8x4 modem that just was limiting the speed of downloads. This has been installed a few weeks and has performed well and I get the rated speed from my cable provider. The setup process with Xfinity/Comcast was surprisingly simple and did not even have to call them as they have a website to handle modem changes now. Hopefully they recognize it as customer owned as that was my previous issues when I bought the first one. Only time will tell if it lasts as long as the previous one, which was roughly 6 years. Very happy so far with it and feel it was a good value unless you wanted DOCSIS 3.1.

Had an 8x4 modem & since Comcast kicked my speed up to 250/20, I wanted to get a newer modem to take advantage of this...but did NOT want to spend lots of $$$ on a current 3.1 modem, with full-duplex around the corner. Instead, this one came up on close-out for only $70. This is MORE than sufficient for my current speed, as well as any conceivable standard speed increases in the next few years.

Comcast told me forever ago that my old Arris SB6121 was out-of-date with my plan, and after being WFH for the last 8 months, I decided it was time to upgrade. NOTE: I've only had this for a week, but no problems (meaning connectivity issues/drops) so far. Speed went from 150 mpbs down to consistently 250, and my plan is the 200 Blast! plan. Both were DOCSIS 3.0 modems, but this one has 8x the number of download channels. Does it make a difference? Nothing appreciable yet, but trying to get ready for next-gen consoles and more WFH for the foreseeable future. Easy to install, and haven't had any hiccups yet. Since DOCSIS 3.1 isn't really something most people need at the moment, this is a super solid modem for most normal internet plans.

Upgraded internet speed so needed router to handle increased speed. Easy setup and has been working great. First bought from AMZN and package came with no power cord, instructions etc. was obviously a returned product. Sent back and ordered from Best Buy. Best Buy sent a new product as expected. Should have started with them.

This Modem was an easy plug in and connect device right out of the box. You MUST register the new internet Modem with your internet service provider before it will function properly. This Modem will handle up to 400MBPS per Motorola’s (manufacturer) technical support staff, and this device is listed on the COMCAST website list of approved devices.

I purchased the Motorola MB7621 modem because of my poor experience with the Netgear CM700. The CM700 dropped connections many times per day. The netgear CM700 has built in Quality of Service (QoS) that you cannot disable which can make it hard for some devices. The CM700 ran very hot, much hotter than my router. The CM700 also has the dreaded Puma 6 chipset, which has many, many bad reviews and known issues. The Netgear CM700 has only 90 day tech support and a 1yr warranty. The CM700 had many, many uncorrectable's on the modem event page . Now onto the the Motorola MB7621. The Motorola has the Broadcom modem chipset instead of the dreaded puma 6. The Motorola doesn't have built in QOS, The Motorola has a 2 yr warranty compared to 1 yr warranty offered by Netgear. The Motorola is lower priced. The MB7621 runs much cooler in temperature and looking at the event page it doesn't have even 1 uncorrectable compared to the CM700 which had thousands. The Motorola MB7621 hasn't lost connection once, compared to the CM700 which lost connections many times per day. Unfortunately since Best Buy didn't carry the MB7621 locally I had to order online. The wait was worth it. Once I received it, I returned the poor performing cm700 to best buy who always has great service. I Have Xfinity Blast.

I had wifi rated up to 300Mbps with Spectrum, but was only getting around 30Mbps with a combo modem/router. I invested in this and an ASUS (RT-AX3000) router in order to work from home, classic, but to also just use Wifi without constantly buffering. So frustrating. But that is a thing of the past, as now I consistently get speeds of >300Mbps! Wifi hasn't been a problem since (~4 months strong). Added bonus, I thought the directions for setup were clear as well. Highly recommend!

This Motorola 24 x 8 DOCSIS 3.0 cable modem was easy to set up. There was no problem getting Comcast to recognize it. The short wait for the modem to be in stock was worth it. If you are using an older modem, do some speed tests as recommended. If you are not happy with the numbers, order this modem before the old one gives out! The modem interfaces perfectly with my new TP-Link Archer C7 router. A great team!

I had an Arris SB6141, several years old but still delivering 60 Mbps just fine the evening I removed it from Spectrum account. Upgraded to this Motorola MB7621 and saw improvement to 95 Mbps during same evening! Next morning at likely less peak demand found I got 143 Mbps. Totally thrilled with this purchase. Heat seems reasonably low. DOES NOT contain the flawed Intel Puma 6 chipset used in many other modems. 2-year warranty. Aces!!!

Super easy setup, Increased download speed 15 MB Ran test 3 times with old modem and 3 times with this one. Definitely improved by at least 15 MB.

If you are looking for a way to reduce your internet bill by leasing equipment from your provider then this is the modem for you! It is only a modem (so for wireless you will need a separate router) but the specs allow for the speed your household needs. I currently have 150down/15up and it perfect for what we do at home. Installation was very easy with the information provided. If leasing cost is a concern then this modem is for you.

Dad was finally getting cable internet and I bought this for him so he wouldn't rent a modem from cable company. This Motorola modem was easy enough set up for him to understand, clear visibility of buttons, and -- nearly a year later-- it has been rock solid. Very happy with this purchase.

I have been very happy with this modem. It works with Comcast and pays for itself in about 8 months. I have used it for streaming TV and other wireless devices, no problems. Setup was very easy and intuitive.