Having a rear view mirror is really nice
I ride a 'bent, so it makes it
that much more nicer - but I like not having to turn my whole body to see behind me
If you'll be riding in traffic, it's even nicer
Oh, and carrying a multi tool is a good idea - be sure to have tire levers if you don't go with the slime tubes and plan on brining spares.
And that's a nice trunk bag - I've been looking for something like that for my racks
I'm either going to make my own tail cone (boat tail for bikes/'bents) and integrate a trunk or just buy one