Ruger introduced a "reverse indexing pawl" on the New Vaquero that aligns the chamber with the ejection rod. I also have a Blackhawk built on the NV frame that has this feature.
The guns built on the larger Blackhawk frame (such as the "original" Vaquero) do not. I tried to unload one and realized how spoiled I am.
Some cowboy action shooters perform a "free spin modification" on the "original" Vaqueros. I don't know whether there may be any drawbacks to that.