I've got the Heritage "Rough Rider" 6-shot .22/.22Magnum, and it's worked very well, so far. It has an investment cast frame, a la Ruger, but everything else is steel, and it feels pretty solid. The safety is unusual on a single action revolver, but works as it's supposed to. These are made here in the USA, which is another point in their favor. They are the same size frame as a Ruger Single Six, and holsters for one will fit the other. Heritage also makes a .32 H&R Magnum revolver on the same size frame.
The Heritage Big Bore single actions in .357 Magnum and .45 Colt are assembled here, but the component parts are manufactured in Italy by Pietta. I'd call them comparable to the Uberti Cattleman line of traditional SAA type revolvers. They look like fair quality for the price, but I'd hesitate loading them up with handloads labeled "Ruger Only." To be fair, I wouldn't shoot the hot loads in a traditional Colt SAA, either.