During the two trials I took part in, no juror other than myself took a single note of the proceedings. We were lucky; our longest case took two days, but even then, fellow jurors' recollections were at odds with my notes, and indeed several different jurors recalled parts of the evidence in different ways. The other jurors were thankful for my notes. How we could have proceeded otherwise I do not know.
I was elected foreman (on the basis of wearing suit, I "must be clever"). Worryingly, some of the jurors lacked the skills, or perhaps the intellect, to examine the evidence before coming to a verdict. A number of jurors admitted they had formed their view on instinct and feelings.
The judge had been helpful when summing up, telling us which issues to consider in a logical order. This ought to have made things straightforward. Some people found this hard, and kept confusing issues. They would come to agreement on certain points so that we could move on, only to open up the debate later, on occasion referring to things they thought to be in evidence which were not.
I believe we came to the correct decisions, thanks really to three or four jurors. Had these people not been there, were they replaced by people similar to the majority, then justice might not have been done.
My worry is how often justice has been done by accident or injustices taken place because of the fallibility of jurors.