So the nice thing about grouped-by-user is that you get the full context of what someone is working on today. One todo by itself might not always be meaningful, but by seeing the other things that person worked on today you get a good sense of what they are doing.
On the other hand, the downside is that every time someone posts a new todo it bumps up their whole list of that day. So as a viewer you start seeing the same content and you're not sure if there's anything you haven't seen it yet further down the page.
Perhaps there's an alternative solution possible. For example only showing the new todos (grouped per user), with the todos you've already seen hidden by a "See 4 more todos…" button. Although that would require us to start tracking which todos you've already seen. Or least a timestamp of when you last viewed the homepage. (anything created after that would be considered unseen).
So the nice thing about grouped-by-user is that you get the full context of what someone is working on today. One todo by itself might not always be meaningful, but by seeing the other things that person worked on today you get a good sense of what they are doing.
On the other hand, the downside is that every time someone posts a new todo it bumps up their whole list of that day. So as a viewer you start seeing the same content and you're not sure if there's anything you haven't seen it yet further down the page.
Perhaps there's an alternative solution possible. For example only showing the new todos (grouped per user), with the todos you've already seen hidden by a "See 4 more todos…" button. Although that would require us to start tracking which todos you've already seen. Or least a timestamp of when you last viewed the homepage. (anything created after that would be considered unseen).