We might be splitting hairs a bit, but I think Seids is a steadier defensive d-man. And with guys like Krug and Bartkowski to move the puck a bit, I'd have certainly taken Seids over Boychuk last playoffs, and today. Obviously though the difference isn't huge either way.
As for being 1 short of a top 4, in terms of looking at it through a Bruins lens, I agree. But when your top 3 is Chara, Hamilton and Seids, you should be able to compete for a Cup when your next 3 are Krug, McQuaid and Miller. It's not Chicago's D or even top 5 in the NHL, but it's still top 10. And if the offense isn't good enough, you got to make some hard choices. Top 10 D with top 5 goalie and a great system should be good enough.