Because this is a chain, you are pretty sure to get fairly consistent food here. Sonny's is Sonny's. I'm not from Dublin, but work here and when I want BBQ, this is where I go. Sure there is Buffalo's and the other chain restaurants, but Sonny's is as good as it gets for a true BBQ experience for me.
My partner likes to go early to ensure getting fresh options at the salad bar. The restaurant is really never crowded and we have always had a pleasant meal here. There are very few diners in Dublin that eat late, so there may only be a couple people eating if you go around 8PM. I like to just get a rack of ribs or a pound of ribs and skip the meals that come with the sides.
For Dublin, where there is not a ton of choices, this is a good bet for a good salad or a very good meat meal. In Dublin, Sonny's gets a Very Good rating.