Which to use: OTS router or Linux-based?

G’day all,
Could someone (or everyone) give your argument on which is better and why for a home user between 1 to 5 users using Dial-up/Cable/ADSL? Must in consider of as many aspect as possible: security, power consumption, price, etc:
* Off the shelf router
* Linux-based router/firewall (e.g. Smoothwall or IPCop)