What about my home Linksys router with its Cisco logo on the front? No mention of that but is it safe?

This is a warning for big, high load carrying enterprise kit. Frankly if you've pissed off someone enough to get them trying to DoS your broadband line, no home router stands a chance, Linksys or otherwise!

Ha ha ha. And you pay double (or triple) for that quality!

All equipment/software contains vulnerabilities - its just a matter of time before they are discovered. It just so happens that Cisco kit is so popular that statistically there's a higher chance of a vuln being discovered (than say a lessor vendor), and that people will go out of their way to exploit it purely for the kick.

these software releases are fairly old - anyone keeping up with bug-fixes,

features etc would already be running the latest firmware anyway

of course, you'll then hit the caveats and bugs in the newer release - but

at least those ones aren't known/published yet! ;-)