Re: We should use neither
I completely disagree with this assessment. I have a failover gateway here, running on a Pi, with an uptime over 376 days. Granted, it spends most of its time idle, unless the main gateway goes down, but hasn't failed once when we've needed it.
It is for a small office and running as a:
DHCP failover node with the primary
Transparent Squid Proxy (with blacklists to protect clients)
Yes, it is a bit slower than the primary gateway, pings increase by about 5ms through it, but keep in mind they're 700mhz - 1.4ghz ARM processors with limited RAM, don't overload them and they do fine.
I also have another two RPis running as remote CCTV cameras (PiKrellCam if anyone's wondering), these have been faultless too. I have two other RPis running Nagios network monitor sending alerts if any problems, which they too have been faultless for over 2 years.
Ultimately, you need to know the limitations of the device you're configuring, i.e. RPis USB + SD controller share an IRQ (IIRC), making them rubbish for file servers using USB NICs, but great for gateways for e.g.
Finally, if your Pi is failing because of USB devices power requirements, get a proper power supply for it. Even the CSI cameras will crash a Pi if an in-adequate supply is used.