Like Randy mentioned there are many threads on the subject.
My personal opinion is that I would use them. I did.
Are they a requirement? No, but they'll help you do a better job.
One lesson I learned as soon as the white paint was sprayed. Every rivet that was a little proud, stuck out like a sore thumb was it was painted. Fortunately, I didn't have many and could easily fix the ones I found.
bob