said by Taylortbb:Some people prefers the Motorolas as they're considered to be more reliable, in practice I think the difference is negligible. The big difference is the Technicolor supports 8 channels while the Motorola only supports 4. Some of the higher speeds (like the 150/10) will only be available to 8 channel modems.
The guy on here that flashes cable modems (and repairs them) has suggested that, based on his teardown, the DCM modems are actually better built and will probably last longer as a result.
A lot of people ascribe reliability to the Motorola modems based on their experiences with the 5100 series, which were very good.
Not that the 61xx's are junk, just that they haven't put in the hours that the 51xx's have yet and anecdotally aren't built any better than alternate modems.
Indeed, there have been some 6120/6121 overheating/failure issues to suggest that they're not as good.
All that aside, to the OP: buying a 612x modem right now isn't a great idea. They're already "outdated", per se as 4 channel devices. If you want a Motorola, buy a 614x or higher to get 8 channels. Since those aren't certified right now, you should probably just by a DCM476.