I originally had been told the 6” slow sink, but I have trouble getting it down. Thinking now I need the fast sink in either a 5 or 6 to get the burning retrieve MB intended.

The answer is in the depth you want it to hit and with what current. You can add suspend dots and/or strips to the front sections or add lead wire or gold tape to the hook hangers if you don’t want to buy another bait. Add the amount that the next heavier sink rate would be if that makes sense. 

48 minutes ago, VolFan said:

The answer is in the depth you want it to hit and with what current. You can add suspend dots and/or strips to the front sections or add lead wire or gold tape to the hook hangers if you don’t want to buy another bait. Add the amount that the next heavier sink rate would be if that makes sense. 

Yeah I’m fishing around 3-6’ on average in varying degrees of current. I can’t seem to get the 6” slow sink much deeper than a foot or two though on a steady retrieve.

Lead wire that BS to your liking. Below is my 6" floater that's weighted to be an XXXXSS for fishing over shallow grass.

22 hours ago, GreenPig said:

Lead wire that BS to your liking. Below is my 6" floater that's weighted to be an XXXXSS for fishing over shallow grass.

Is fast sink too fast?

I don't personally own any fast sink BS's. I modify SS and floaters to achieve the ROF I need. Really would depend on your river's current and the depth you want to cover. Only reason I'd ever buy a fast sink, is if I was gonna do a top hook mod.

With that said, I don't chase smallmouth and rarely fish flowing water. Hope some of that helps you in your decision.