The best way to get "comfortable" with a knife is to use it often. If you want a shiny new toy in an emergency, then you need to have two, one to use and get used to and one to gopher-hole with your kit. Personally, I use all my gear whenever I get the chance, then replace/duplicate it so I've always got a spare. Not only does this keep me familiar with it, but it solves the "when to rotate?" question. Some of the more expensive stuff (Hennessy hammock) doesn't neccessarily have a twin, but it's been used enough to prove it's worth/usefulness, and, who knows, maybe if work picks up, I might go ahead and splurge on a new one so I'll have a spare-to-share. Besides, extra gear can always be bartered off for something that just wasn't thought of.

Troy