Interesting results, or should I say not what I expected:

11-28 best effort (11/13) http://www.strava.com/activities/948...nts/2009091409 time 1:15:25 , avg cadence 80
12-30 best effort на (yesterday 11/17) http://www.strava.com/activities/957...nts/2032005614 time 1:11:42 , avg cadence 79

My guess cadence dropped because I spent most of the time on 27 cog vs 28 before (12-30 does not have 28, it has 27 instead).

Same picture on the final 3mi stretch:
11-28 http://www.strava.com/activities/948...nts/2009091361 time 23:56 , avg cadence 73
12-30 http://www.strava.com/activities/957...nts/2032005614 time 22:54 , avg cadence 72

Claiming "The Wall" http://www.strava.com/activities/957...nts/2032005573 on 30 is definitely easier, my left knee feels so much better today where on 28 there was just too much stress.