Most suspending jerkbaits with the short bill dive to around 5 to 6 feet...what's the difference in action for the deeper diving long-billed baits? Preferences?

If you work one on slack line the same as you would a shallow model, there is very little difference. I will take a few more cranks of the reel handle to get it down to depth, but as long as you avoid a few brands that have a wider bill (wider wobble when jerked) the action will be about the same.