I don't think I have ever heard a good word said about that modification.
I think the worst possible choice would be to buy an unaltered Old Model for the purpose of having it converted. (Note that if you send in an Old Model for any unrelated purpose, you get the modification automatically. I don't think they even send you back the old parts any more.)
Go New Model or get by with a Fiveshooter.
My only use for a single action is CAS, which only allows 5 in the gun, so I am good with original lockwork whether Colt, Italian, or Ruger.