Hi. Should I replace the modem that came with our dsl subscription which is the Zyxel P-660R-D1?
What brand is a good replacement if this modem is not that good? We use it with a router to share between two computers. Thanks in advance. Gbu.

I have this modem, as Earthlink wants to replace modems every 2 years.

Pros:
It is smaller than the old modem, and has 1 less green light than my prior modem, for a total of 3 green lights, and one yellow light lit, when everything is working fine.
Cons:
The internal OS (or software) of the modem is not easily upgradable, if that would become necessary.
With the Earthlink's, ISP service, the modem's clock is consistently wrong, and just reflects uptime.
Occasionally, the 3rd green light will go out for no apparent reason, requiring a hold-in of 20-seconds of the reset-button of the modem, and a re-login through the browser (could be the ISP's fault, not the modem).
The re-login through the browser can be problematic if the ISP's user's password is entered incorrectly the first time, as subsequent logins with the correct password are rejected -- the workaround :
make sure that the browser's URL is always:

http://192.168.1.1/setup

before entering the username and password.

All-in-all, a typical DSL-modem.