When I got my 627 Pro I was sort of surprised by the heavy DA pull. I loosened the main spring screw a bit just to where I noticed a likable pull. Then I dripped some gun oil down into the trigger and hammer areas that contact metal.
This made big improvement in trigger pull to the point I am very satisfied with it now. People say don't mess with the main spring screw because it can cause light strikes but I have had no problems with it. Jerry Miculek shows adjusting the main spring in his trigger job video. If an expert shooter does it then I am okay with it. Granted you want to check that you don't back it off to much and get light strikes.

My 627 Pro now has probably the best trigger of all my revolvers.