How can there be a difference, you ask.
Like most knitters, I often have more than one project going at the same time. Normally, I have one project downstairs next to my comfortable chair, and another upstairs next to my recliner. Never waste a minute.
Recently, in order to have the right size needles, I picked up a pair of metal -- I think it's aluminum -- needles, and rediscovered something I had forgotten since becoming accustomed to wooden needles. Because metal needles create less friction, they are much faster.
They do have a major drawback, regretfully. At night the shiny reflections can cause considerable eye strain, hence as long as I'm using metal needles, I'll be forced to divide my projects into day knitting and night knitting.