Really slow upload speeds
I currently had the business deluxe connection (150/20) and the uploads speeds never reach more than 2Mbps. Before I signed up for the contract, I was promised the numbers would be the lower limit for the actual speed I'd get during service. This has been consistent. At first I just chalked it off to new connection/intermittent issues. But it has been consistent across multiple devices. I even disconnected all devices and just tested one device exclusively. Download speeds are great and no problems there. But upload speeds are completely unacceptable.
Edit: The solution from Comcast_Phil seems to be getting a new modem, since the bootfile in what I have is not compatible with the business class connection. Getting one and will report results after that.