Recusant
Hellcat
I think you heard wrong. The Security / Service, Speed Six can have a very nice trigger pull. Mine is very good and totally factory. I do think that as a whole the S&W has a better average action on them. I like the S&W action better than a Colt's (but that is me) The GP-100 and SP-101 I am not familiar with but in the Redhawk the mainspring does double duty as the hammer spring and the trigger return spring and can be problematical.
I think the time period in which a Smith, Ruger and Colt were manufactured makes a big difference in trigger pull. Back in the 60s and 70s most parts were machined steel in the factory and most factories had gunsmiths who had been turning out revolvers for years. As the use of MIM parts increased this had an effect on the smoothness of triggers actions. Also the manufacturing process for MIM parts as a rule is jobbed out to companies that specialize in metal injection molding. The other thing that may not come to mind is the fact that company lawyers have become involved in the the manufacturing process in regards to the how many pounds of pressure on the trigger it takes to drop the hammer.Trigger on my SP101 is fine. Of course T man's requirements for a trigger on a revolver are likely more evolved than mine.