I'd say both, with a caveat about each.
As for the run D, it has gelled over the last three weeks. Stephen Davis got some good yardage last week, but that came late in the game when we were more in a prevent mode. The caveat here is injuries. We have been missing Vonnie Holliday (DE), but he is due back Monday night; and our other DE, Joe Johnson was lost for the year one week after we lost Holliday.
The pass D is excellent. The cornerbacks have played well, and our safety situation is finally starting to settle down. The caveat here is injuries, too. Starting left corner Mike McKenzie, a viable Pro Bowl possibility, has missed the last three games with a strained groin. He is due to return Monday night. Free safety Darren Sharper, a Pro Bowler, has also been injured. He, too, will be ready by Monday-week.
The good thing about these injuries is that it has forced second and third string guys to the forefront, and they have done more than just perform adequately. Aaron Kampman, a rookie, has performed well in the place of Holliday, and will actually probably retain the starting job at least one more week, even though Holliday will play Monday. He is a tad undersized, but has a huge motor and never quits. He is always around the ball. Sounds like Jason Taylor a bit... he doesn't have that talent or those physical skills, but the kid is a player.
Losing Joe Johnson has forced us to press others into service, such as Steve Warren and Rod Walker... both who have performed very well. Last week, against Washington, we started Kabeer Gbaja-Biamilia (a.k.a. Kaboom, KGB), our pass-rushing specialist who we usually reserve only for passing downs. He held up well against the run, which made us happy. There is still a concern that he can hold up all season there, but if he starts against Miami, he will be plenty fresh after a week off, and especially since Sunday was only his first start. Finally, as to the D line, our #1 pick from the 2001 draft, DE Jamal Reynolds (Fla. St.) has SUCKED for two years. Until Sunday, that is. Against Washington, he fiiiiiiiiiinally looked like he was catching up with the pro game. Like I said, the D line has gelled very well of late.
Let me take a second and tell you about one the guys that got thrown into the fire in the defensive backfield: safety Marques Anderson, #20. This is a rookie from UCLA who has played VERY well in his time on the field. For his work Sunday-before-last against New England, he was named Rookie of the Week by the NFL, and was a final four nominee for the Dockers Defensive Player of the Week for the entire NFL (as was Jason Taylor, by the way). This kid is whip-smart on the football field, and brings the wood when he tackles. Our coaching staff is going to be living in denial if they keep him out of a starting job much longer, even when all our guys are healthy. He has CB-quality coverage skills, too. Keep an eye on him.
I know this sounds all rosy, and kind of fan-oriented; but honoestly, this D has really gotten better in the last month.