in my enterprise world, production systems are fully redundant, and have staging servers running identical software configurations. all upgrades and upgrade procedures are tested on staging before being deployed in production. quite often, the staging systems double as the Disaster Recovery systems, but thats another story. virtually all production systems either have a schedulable downtime (2am sunday morning?), or support rolling upgrades with no downtime (such as our 24/7 factory operations where downtime == no product).
personally, I'm very glad I work in development, where our informal SLA is more like 9-9 5 days/week (developers like to work late).
Sounds like you have a dream job John! At the very least for a company that spends money on proper hardware!