Stack it high and watch it fly

I did not run Ice Age in 2008 because of a stress fracture. In 2009 the goal was just run by time, do a bit of faster running and go out at Ice Age at training run pace.  I pulled weeks like this starting from January:
6:46:44
7:12:37
7:22:34
7:37:27
7:59:30
8:44:28
7:48:17
10:56:28
6:22:33
10:04:11 w/ 10k 41:53 and 4 x 100 (2)
8:52:28 w/  8 x Lowell Hill
10:19:21 w/ 6 x 100 and 8k 32:00...6 x Glacial Cone hill
9:08:19 w/ 6 x 100 and 8k 31:55
7:02:15
7:34:41 w/ 30:00 tempo.......6 x Lowell Hill
8:34:01 w/ 5k 19:32
4:13:20 w/ 15 x Horab hill
4:17:40 w/ 10 x Horab hill
Week of Ice Age ran 5.0 Tuesday and 3.4 Wednesday and finished Ice Age in 7:20:57 with virtual even split pace in the first and second halfs of race.

Here are the runs around 2 hours or more:
1/18 = 2:20
1/25 = 1:54
1/31 = 1:57
2/1 = 1:51
2/7 = 4:21
2/15 = 2:04
2/20 = 3:06
2/22 = 2:01
3/1 = 2:30
3/6 = 3:10
3/15 = 3:21
3/21 = 3:10
3/22 = 3:12
3/28 = 3:07
3/29 = 2:05
4/4 = 4:06
4/11 = 3:00
4/18 = 4:30
4/25 = 3:00
5/9 = 7:20:57 Ice Age.

I look at this and yes...it is consistent solid work, but it is not over the top.  It was doable and possibly without knowing it I was going to just the point where it was enough and stopping.  I mean I only did 10 speed/hill type workouts and the hills were small to medium.  Like most I want and can train way beyond this, but does it always work?  It's looking at stuff like this that makes me evaluate stuff all the time.