lxsw20: The Vodafone one is the HG659, which had firmware issues, you will find if you do a search on here. Apparently new firmware has fixed this. If not you can flash onto the Spark firmware.
IF you're using it as a router why would you switch off DHCP?
Good advice - and there's no issue flashing Spark firmware onto the Vodafone version?
It's to act as a ethernet switch/wireless AP not a full router; it is located at the other end of the house to the Fritzbox and provides wired connections for our fixed devices in that end of the house (Tivo, Squeezebox, Fire TV) and wireless internet for the same. I'm not big on networking at all, but my understanding is you shouldn't have more than one device handing out IP addresses, and in our case the Fritzbox fulfils this role.