My advice is to keep a balance in your plug bag between small plugs and big plugs. Yes, sometimes smaller can be better. Most surf fishermen make the mistake of only stocking big plugs, especially big swimmers (I'm talking plastic and wooden swimmers of 6 inches or more). Many fishermen think big plugs will catch big fish. That thinking works out well when big bait, such as menhaden, mackerel, herring and mullet are around. Remember that you are trying to imitate the bait that stripers are eating when you snap on an artificial. What happens when you have small bait around such as bay anchovies and peanut bunker that measure only three or four inches in length? Only a small plug will imitate that baitfish. Last fall I saw this played out many times along the oceanfront. There were days with tons of bay anchovies around along with calm and clear water. On one day in particular, my son Ben was nailing one keeper bass after another (up to 35 inches) on 4 inch Bombers. These fish were super fussy and that was all they would hit. A lot of frustrated fishermen who had only large plugs in their bags went fishless.
This is the first late winter ever that I have been catching more wintering over fish on small swimmers than on jigs. Plugs like the 4 inch suspending Rapala X Raps have been hot and I suspect they will be hot once the new fish arrive. Don't be fooled into thinking these small plugs will only catch small fish. Take a look at the right of a picture I took a couple of weeks ago of a large winter fish that was caught on an X Rap.
So my strong advice is to stock up on small swimmers (4 inches or less). They are hot when the small bait comes around. And, yes, they will catch keeper fish.