I used Comcast for many years for internet and cable viewing, always using my own modem and separate router.
Within the past year or so, I went with their triple play, which required replacing my modem to one with telephony capability.
To save time to research, and to make the conversion as painless as possible, I went with their router/modem combo.
It has worked absolutely fine -- no issues since it was installed and wifi coverage is great.
I said, I am addicted. Plus all my family and friends have my landline number as well as millions of spammers.
So far this morning I have had 4 spam calls. Maybe I should consider ditching my land line and going for a new number.
This may not be a big issue once you convert. With Comcast you can sign up with a nomorobo, a service that does an exceptionally nice job of addressing spam callers. The phone rings once, then the service takes the call and presumably drops it... no more hassle.