Bob,
The 12b weighs 6lbs. 8oz. and has a neutral balance. The 20b comes in at 6lbs. 2oz. and balances the same. Both are 26" and are choked IC//MOD. At the neutral balance they are lively without being whippy. I shoot them well even at targets simply because I have developed the necessary muscle memory needed for the light guns. I stick to 7/8 oz. in the 20b and 1 oz. for the 12b. and the recoil is light.
That 12b has been my main bird gun since acquiring it 15 years ago. My new 5 lb. 12 oz. 12b Churchill has become my bird gun now and it's working out nicely with RST 1 oz. loads. It's great for all day carry in the North grouse woods.
Hope this helps,
Karl