Until quite recently, I only used the poker room notes facility very infrequently. However, as the facility is there it seems stupid not to make use of it. So, over the past 2 or 3 weeks Iíve started to use it more often. At present, I mainly use it to build a better idea of villains likely preflop raising range. For example, one player in particular I have noted seems to raise from any position with a suited ace, plus the standard premium hands. Of course, itís possible to put a player on a likely range based just on the frequency of their PFR, but having the notes there I find it quite useful when deciding how to act on their raises.
I would not want to make copious amounts of notes as Iím concerned that could be counter productive. However, I would be interested to hear if others use the note taking facility and what they use it for.