We have only about four hours in Dublin on an autumn Saturday evening. We are coming in from Dingle to fly out of Dublin in the morning. What would be the best use of our time to get a feel for the city?
I'd probably walk around the historic center of town and go to Temple Bar to listen to some music.
If you download the Rick Steves Audio App, there's a Dublin City Walk 1: South Bank tour that covers the south end of the historic center. It's about 90 min, and will walk you through the point of interest.
I'd avoid Temple Bar and do something on the north side of the river - music at the Celt (food) or Cobblestone (no food) is a lot more authentic and doesn't involve throngs of drunks. If you're staying on the south side, maybe The Brazen Head for music and dinner.
You can sample The Temple Bar on their live cam
https://www.earthcam.com/world/ireland/dublin/?cam=dublinpub
I would second the Brazen Head. Had a great evening there with music/folklore/famine history talk (mentioned in RS) and a very good meal. I think I remember reading that that event has moved to a different pub now.