If you’re a Time Warner Cable subscriber for Internet access, and you’ve historically been on their top tier consumer bandwidth service, “Ultimate 300”, you’ve been paying $109.99/mo. (Assuming you’ve subscribed longer than the $64.99 12 month promotional pricing they tout on their web site.)
NEW MODEM REQUIRED
It turns out that you also have to buy a new cable modem to support all the new bandwidth and all the bonded channels required for 300Mbps/20Mbps. (ARRIS / Motorola SB6183, for example)
I had the ARRIS / Motorola SB6141 and it indeed only supports ~100Mbps d/l speeds. (See the snap shot of SpeedTest to the right of what was taken using the SB6141 on a 300Mbps plan)
SHUTTLING DOWN TO A LOWER PLAN
Alternatively, it also turns out that if you shuttle down to the old 100Mbps/10Mbps, which may be all you need (aka “Ultimate 100”) you can save $40/mo on your bill and pay just $69/mo for an annual savings of $480/yr. (See the snapshot of my bill from the previous month and the coming month)
HOW DO YOU DO THIS?
You can’t do it online. Call (855) 243-8892 and navigate around to “Reduce Service”. Yeah, they really bury it in there in the same way that they hide what their retail charges are per service outside of the promotion.
REGARDING RETAIL PRICING
All their retail pricing is available in the link below – you have to pull down a PDF price sheet/rate card to get the price you’ll pay after their initial 12mo promotional pricing. In West Los Angeles, their pricing is in the snapshot to the right and is “Extreme + Ultimate XXX” if you want 100Mbps or more which ranges from $69-$109.
http://www.timewarnercable.com/en/support/account-and-billing/topics/retail-rates.html
kurtsh
Kurt's Thoughts 
Thanks for this information. I currently have their 300Mbps service and I was wondering why it was only maxing out at just barely over 100Mbps. I found this odd as my networking hardware supports the Gigabit speed and everything is AC protocol. Turns out I have the same modem that you mentioned (SB6141). I purchased the SB6141 just to avoid the rental fee. I believe I started at their 50Mbps speed tier, but I never thought I would be upgrading to their 300Mbps tier over the course of my service with them. I require the bandwidth because I play games from the Cloud (NVIDIA GeForce NOW) and I really don’t like games taking a long time to load/buffer. While gaming from the Cloud I have experienced low bandwidth warnings from the NVIDIA SHIELD (probably because of the SB6141 bandwidth limits). You recommended the SB6183 for the speed upgrade, but I went with the model above that, the SB6190 (Cable Modem version only) just to make sure I get the speed I have been paying for the past few months that I have not been getting.