said by Vince:
I stopped and picked up a modem from TWC today. They gave me a Ubee u10c018.80. I just got it hooked up and even though the DL speeds seem slightly lower(could just be a lot of traffic right now), the UL speed seems much better and more consistent. Now my question is: Is my Zoom modem definitely bad or could it still be an issue with the upstream connections? The Ubee is only DOCSIS 2.0 while the Zoom is 3.0.
It could still be an issue that only impacts DOCSIS 3.0 modems. Therefore you really need to see if they will give you a DOCIS 3.0 modem to test with. Anything else isn't comparing apples to apples.