It's not fear of backdoors that make me run a specific router.
If I want free wifi access around the country (via BT Openzone) then I need to run BT's router (which includes the magic to run a separate managed public Wifi access point via BT Fon).
It's annoying, but I can live with it (especially when they get around to upgrading my cabinet to FTTC and I get 60Mbps/20Mbps).