I'm playing only on mobile at the moment so not able to take notes in the client. Although with the mobile
App being more limiting it means that I generally only play 2 tables at once so am easily able to keep an eye on all the play and remember what players are doing. It's not as efficient as taking notes within the client but it does the job for now.
Once I'm back to using my laptop again then I will certainly back to making some notes again. Admittedly, moreso than actually taking notes, most of mine was done simply via labelling people. I'd make notes now and again but, for the most part, a simple label is enough. If someone's a nit, a maniac, a crusher, a loose bounty hunter etc, a label will distinguish them easily