said by Lar:
The reason that it might be good for a cable provider to be able to upgrade your modem is because from my understanding only the ISP is capable of doing these upgrades on your modem.
If it ain't broke (and it ain't) Mediacom does not need to try to fix it via firmware.
IMO a 6121 firmware "upgrade" is only going to benefit Mediacom, not me. They would have control over a modem I purchased.