Years ago in Texas, I caught lots of bass during the winter on a deep diving Bagleys Honey-B. I'd love to have had a Shadrap that small then. I threw those lures on a spinning reel. I was always fishing rocky areas with no chance of fish diving into brush. I have both sizes on the way now from Tackle Warehouse. I bet the #4 will kill crappie too.
I fished with a lot of guys that couldn't cast a spinning reel, they'd release wrong and the lure would go straight up.
As I've said, each is a tool. To be an efficient fisherman you need to know how and when to use both.