As mentioned before, try the two lengths for a side by side comparison. My husband used to shoot 26" when he first started. Next was 28". When he bought his most recent new shotgun he got 32" and shoots it better than he did his old 28" (which by the way has extended choke tubes so it's basically 29").

I started with 26" on my 12 ga. I have 26" on my 28 ga. My next 12 ga will have 28".....
The extra length can help with follow through.