Mike, anyone who feels undergunned in a dove field with a 20 is badly mistaken. There's not many things that I feel I know a lot about, but dove shooting is one of them. I farm and grow several crops that attract doves, and we shoot them a lot. I'm 59, and celebrated 50 years of dove shooting last year, growing up on Grandaddy's farm shooting doves and quail. I started out as a kid with a Rem. 11, 20 ga., went the 12 ga. route for many years, and for the last 8 seasons haven't even touched a 12 for doves. As a matter of fact, for 98% of dove shooting 7/8 oz. loads is aplenty. I have a Beretta 687 SP II Sporting that has killed nearly 8000 doves here and abroad in the last 8 years. I have a group of friends that get together with me each year for doves. We shoot a lot. They have been amazed for awhile now at the effectiveness of a 20 on doves. An IM choke with 7/8 oz. of 7 1/2s will kill a dove dishrag dead so far out that it still amazes me sometimes. I kill doves regularly out to 60 yards, occasionally out beyond 75. Not wounded, killed dead in the air. Not just a golden BB in the head either.
As to sporting clays, I compete regularly during the spring and summer. Though I use a 12 for the main events, my regular shooting buddy tells me that I ought to use the 687 with 1 oz. loads in the main events. It is very effective.
If you take a leap of faith and get a really good 20 that fits you, that you can choke to suit the situation, you should never feel undergunned. I certainly don't. OTOH, I DO NOT consider it a true duck gun for anything other than teal or beaver pond woodies.
Stan