The arris 852gs are junk, the 862gs are better, but either way, the comcast gateway is a piece of garbage in my opinion, but what do i know im ajust a comcast tech lol.
Word of advice, arris has done everything right up until this product, if you have cdv, request an arris 722, and get a good netgear router. Low signal will cause the gateway to drop block sync from time to time if its bad enough, but the wifi is a problem caused by the unit itself. The SMC's were better than the arris, but as a tech, I just dont like them, too locked down, and much better performance from a good router in general.
If you dont have cdv, and you use the gateway as a wireless modem only, then purchase yourself a motorola SB6180 call up comcast save your self 7bucks a month in owning your own modem, and then buy a wireless router. Tell them send a tech to Pickup your old gateway. If need be tell them you want a SRO, this will make it a free visit (SRO is a type of order in the system, stands for special request order) Tip the tech like 15-20bucks and hell probably set your router up for you if he has the time

If you need assistance that is.