Customer Ratings & Reviews

We bought this to replace the Comcast modem we rented for too long! No issues so far.

I really can't provide a review based on it's performance because I never opened the box. I am sure this modem is excellent, but as a Spectrum Internet customer, they gave me one at no charge. I am finding the Spectrum modem to work extremely well so I returned the one I purchased from Best Buy.

Excellent piece of tech gear for the price. Replaced outdated modem router combo from internet provider. Great for streaming live sporting events very little to no buffering it is Night and day over old equipment

Awesome modem, bought this for my daughter for her first apartment, works great

Hey put together a gaming computer and wanted it real fast also didn’t want to take away speeds from my family as they used the internet as well this thing is a beast 16x faster then the one given from spectrum a must have

Love this product. Didn't lose any speed. Comcast has actually stepped up their game with their modems and routers. This was a no brainer though as it'll shave off the rental fee for their modem. It will pay for itself in no time.

Purchased this Arris model because it was DOCSIS 3.0 compliant and was reasonably priced. My older, non 3.0 Arris modem is the subject to a class action suit in California, for a know bug which causes frequent reboots. Docsis 3.0 removes this issue.

This is a superb modem. I just wish my ISP hadn't locked me out. I combined it with my NEst router.

Great! Works well with Xfinity. I needed a new modem and I was going to get the more expensive one from netgear but this works well with my blast package with Xfinity.

I purchased this and a google WiFi to replace my xfinity router modem. I must say it was a great purchase. I faster service through out my house and zero lag!

Comcast said, they no longer support Surfboard 5121 this replacement is on the list of supported devices so I ordered this one. The tech description matches the more expensive cable modems so cost and specs drove my purchase.

Works great for what I needed and appreciate the easy to install instructions

Arris surfboard is always good.Lasts for 5-6 years.

I bought the modem and the night hawk x10 together I did a speed test both before and after. I gained on average with this combo of 10mb down load and 4mb upload. Much faster modem than what Spectrum’s gives you.

Finally enjoying my internet after having it for over a year with constant prob! I have an Apple airporter extreme and express that I use and had nothing but issues with Comcast modem!! Picked this up on recommendation from Bestbuy employee and it works like a charm!! No more rent charge for modem that doesn't work! Thanks Geeksquad.....

My old modem died so needed to buy a new one quickly. This one made everything function again and at a higher speed.

I explained my problem to the salesperson and they gave me several options until we narrowed it down to this. It works like I was told it would and does exactly what I was told it do.

Finally getting good internet ...upgraded from a SB6141 and what a difference... getting consistent speeds all day long... buffering not coming up anymore on internet and tv that used to happen before

My old Modem was making my connection to the internet hit or miss to say the least. I thought it was my computer or software. My E Mail kept locking down. I replaced the modem and a new Router and the problems have seem to go away. Also it has cut down on my calls to the Geek Squad.

I bought this for my Xfinity/Comcast broadband service as a replacement to the leased modem. It works just as well as the one I had been leasing and has been working fine so far. I have had this for about 2 months so far. Saves me money on my internet bill as I don't need to lease their huge modem this one is less than half the size.