I think that many factors need to be taken into consideration.
English Driven days usually involve the use of vehicles to take you to each drive so for comfort and recoil absorption the heavier gun makes sense.
Pigeon shooting over decoys usually involves transportation and then decamping to set up a hide, so a heavy gun to shoot 90 odd birds makes sense.
Walking 15 miles over a heather and bracken strewn moor to shoot grouse would require carrying a lightweight gun (or using a loader to carry your heavy beastie)if it was all walked up I would prefer a lightweight.
Joe Nickerson went from 12 to 20 to 28 guage as he grew older.
At Dig's age I would suggest he cut out the cigar's and shot a .410
Every gun has its place in your cabinet, it's really a question of horses for courses.
Incidentally I think it was W.W.Greener who suggested 96-1 as the gun to cartridge ratio.
