Joins and parts are hidden by default, there's a checkbox to show them. Nick changes are shown by default so you know if someone changes identity, which is sometimes important context.

Personally, I am glad the days are different pages, it makes it easy to tell if there's any new messages since last I looked at a glance because I don't have to look at date stamps. The only real downside is sometimes I've missed the occasional 23:55 time stamp message because I thought I saw everything in the previous day.