I've tried my hand at Jitterbugs quite a bit over the past year, throughout all hours of the day and night, all kinds of weather, and from all over my pond. I tried them at the times and conditions that are supposed to produce with Jitterbugs, yet I've never got so much as a strike on them. However, buzzbaits in the exact same colors cause the fish to go wild, and I can at least get a strike nearly every time I throw one and catch a good amount.
So for me, I don't consider Jitterbugs to be a really great bait. It's possible that pond-fishing is the cause of my troubles with them. As with anything, I guess it's best to buy one or two and give them a try. Even though I've only been fishing for a couple of years, I've already learned that trial-and-error is one of the best ways to learn what works. They work great for most people, maybe I'm just weird.