How can I make my garage door quieter?
I repaired and installed residential garage doors and openers as well as commercial and industrial doors and operators for twelve Years. The steel rollers don't make a really big differance. They will click as they turn if they are a year or more old but that can usually be stopped by using a lubricant.  WD-40 is great for cleaning out the grime/dirt but doesn't leave a residue being that will keep them quiet.

You are going to notice a big difference if you change your opener/operator to a belt drive though.

My recommendation is to buy a belt drive operator from a dealer. I say a dealer because they get the solid one-piece rail, whereas the 'sears' ones have to be assembled and retightened once every year or twp.