Cadence is important and very personal. The important thing is to be able to relax when you need to (e.g. rolling along in a peloton) and use a suitable gear for chases/attacks, when you might dip into the red. Overall being "on top" of the gear is the most important. Having seen testers struggling to get what they believe is a big gear to make them faster (wrong in most cases), what really matters is speed. So for most people in a road race the cadence around 90/100 works, slightly less in a TT where a slightly bigger gear is used. Best Grabsch may have a lower cadence, but he always does, and it works for him. We all have to find the right one for us, and apply the knowledge to best effect.