Few more notes on my O/U experience.Irrelevant. I asked what people with a lot of rounds would choose and why.
I started in 2005 with a new Ruger Red Label All Weather in 12 ga. After 2 years I started having mechanical issues of light strikes. I put up with it for awhile then spent money on a gunsmith. After another year the issues came back again. Another trip to the smith and it only lasted another year. Not a good record for maybe 4k of shooting with a gun that cost $1300. I sold it and bought a used Browning Superposed from 1956.
I paid $900 for the Browning which has seen at least 4k of shooting since I've owned it plus another 200k of the owner before me and it's still going strong. I would have no hesitation in buying a used Browning or Beretta, they are solid performers.
Looking back to when I first wanted an O/U, I was told stick with Browning or Beretta and you can't go wrong. The Ruger Red Label was a lesson of what not to buy, and I still have the bad taste of that mistake.