Christopher was our teacher for a 4 day Evault backup course. Nobody cares about backups, really. Nobody. also nobody cares about network-usage, as long as performance is acceptable.
Christopher cares about both, and was able to make the 2 most boring topcis ever interesting, to a point where i still apply the tweaks he mentioned, and still consider to buy one of his books.
Christopher has a pretty unique teaching style, where his goal is not to read the training documentation to us, but to genuinely attract attention, allowing his students to learn stuff.
Being a parttime teacher myself (programmingskills to 9yr olds), i have adopted some of his techniques to keep easily distracted individuals on topic, and wanting more.
He taught me Evault, and then some.