It's not needed for most security applications. For multipurpose servers, VM hosts, etc. , yes, IPMI and KVM over IP is a good thing to have. Not necessary for UTMs.
I have IP based KVM & serial access to most of the devices but that's usually just for basic diagnostics to dtermine the source of a "Internet is Down" complaint. Most any problems beyond that I have to go onsite anyways so my cisco cable and USB Crashcart adapter are my usual freinds.
I'm not trying to suggest out-of-band functions are required for all environments/implementations.
Some (many?) ASG/UTM/SGs units have never, and may never, in their deployed lives require keyboard/monitor/USB/CDROM intervention - but I don't think that means nobody could/should ever make considerations, or provisions, to reduce some of the pains that can come with needing such interventions for their own environments/implementations.
I've used all of the above (including nothing) in the past - depending on the requirements and budget of the operations/projects.
Out-of-Band access can help with: Limited/restricted physical access environments Business location/hours and IT staff location/skill/hours distribution disparities Risk management: time-to-identify/recover/repair
