I absolutely hate it, it sucks any fun and enjoyment I get out of this lifestyle. Personally I know a lot of people are number obsessed, but I think that only helps a small small percentage of people who's brains work like that...for me, it is the opposite of effective.
I never will, I generally remember how much I lifted last time I was in the gym, and I also don't really care, I'm in there to develop muscle not satisfy a math equation. It CAN BE VERY HELPFUL FOR SOME, but I am a very free brained, creative type and I absolutely am against bringing that kind of stubborn documentation into any area of my life...