what is the actual benefit of expensive crappie rods vs cheap ones (<$50ish)? If you're slip-cork fishing, it's irrelevant and when I'm jig fishing, I've never had any trouble seeing or feeling even the slightest little bites. Most of my bites come on slack line anyway, on the fall, so you don't feel it, you see the line jump/twitch.
I hardly ever fish with bait, but I think it's something of an advantage to have a decent quality graphite rod for fishing jigs. Anything that gives you more sensitivity has gotta help a little. I build my own crappie rods and use a 7' blank light action that only weighs 1.3 oz. My thumb is over the line and the forefinger is on the blank; I don't think he can hit without me feeling it.
But I see folks fishing with those 10' rods and I don't understand why.