Re: the bolded, that's an interesting question. One could argue that Antowain Smith on the Pats was a better, more reliable player than the fumble-prone Henry, but Smith (along with all the other Bills backs from that era - Linton, Bryson, etc.) was a solid 3..7 ypc guy for the Bills. Plus he had turf toe in 2000 and looked like he was running in quicksand as a consequence that year. More generally, I think a lot of the poor RB production in that era was the line, which wasn't very talented at all. Regardless, with NE Smith had two very good Super Bowls, and I value postseason play. He rushed for over 200 yards in the postseason in 2001 and 2003 with zero fumbles. Against TN for the Bills in 1999, he had 14 carries for 79 yards and 2 TDs. He was a postseason gamer for the most part.
Marshawn Lynch is going the HOF, but it could be argued that Jackson achieved the same production. Lynch was the better player, to be sure, but maybe it just wasn't ever going to happen in Buffalo for him. But generally speaking, you're right. Hell, the last good year OJ ever had was in Buffalo.