Round Baler Rolls vs Belts

Let me start off with "I know NOTHING about round balers"

 

I was watching a video on Claas rollant balers and it made me wonder, are rolls better than belts?

 

Do they give longer more trouble free service?

Are the bales better formed, especially in the variable density ones?

 

I'm just curious and if some of you have used these systems don't be shy to express your opinion.

Round Baler Rolls vs Belts