I posted earlier that I have four lights in the rear, but after some observation and thought, I don't think that many is really necessary.

I say two decent lights is all you really need. I say two because of the "redundancy by design" concept. You could have one uber light, but if it fails, then what?

I'm going to move the 4D Toplight from the seat post back to the rack (where it was designed to be) and the NR Cherrybomb will either be on the seat post (currently just under the wedge pack) or the helmet, depending on what and where cargo is on the rack.