I am curious of how many people keep a log of their workouts. I personally do not like it and feel it slows me down.
You have to take SOME rest between sets, so how does it slow you down? Just write out the long stuff at home so you just have to fill in little numbers. Ever have to mess around with a seat position or grab the wrong weight? THAT will slow you down. I like to know exactly what I did before so I can guage my progress.
However, for me, only being 5 months into it, I just change things around too much to remember them yet. Maybe you could just do it once a month or so to at least have a good record of what you do incase life throws you a curveball and you miss some training. I keep all of my logs in a folder just incase.