After a few years of trial and error I settled on the Gamakatsu Round 211 jig head in 1/8th oz. I find that the hooks are super-sharp and the short shank makes hookups more consistent for stream fishing smallmouth bass.
With this weight, I can fish the deeper pools or tail-out areas. Riffles can be fished with a faster retrieve as well as the rod tip being held higher. Just be careful not to high-stick the rod when fighting a fish.
I have zero scientific evidence to prove my theory other than my fishing journal which shows on July 13th we caught 10 Velox using a generic jig head as opposed to July 27th where we caught 82 using the Round 211. It might have been a banner day where all the planets were aligned…but the Journal says otherwise! As with fishing in general….Your mileage may vary!