Okay, I gotta chime in on homebrew 'trigger jobs'. The best is simple - dry-fire the poop out of your new S&W. Make sure it is clean inside - and add a little lube (oil). The best way is to flood innards with RemOil aerosol - with the sideplate removed - and add a drop of gun oil (I like Kleenbore Formula 3.) on the axles and wear surface. If you are squeamish at all, just use the little tube and get it in everywhere without removing said sideplate - hand, bolt, trigger, hammer, etc - wrap the gun in clean paper towels and shake. If any dark residue, actual metal, appears from one of the openings, repeat. Dry the outside - and dry-fire 1,000+ times, changing hands often... and wrap the blister from the sharp edges before it pops! Repeat the RemOil flush and lube, however you first did it. The trigger will be smoother... and, appear to require less effort, although your finger may just be that much stronger.
About softer hammer springs in that .45 ACP - if you use commercial ammo, and cannot insure you will have Federal primers, don't lessen the hammer spring strength! If you ever may want to compete with it - or ultimate follow-up speed shooting is important - don't change the trigger rebound spring - even Wolff and, I believe, J.M. will caution you about this. Mine has a reduced effort hammer leaf - but I reload solely with Federal primers. Don't forget, the strain screw, at the bottom front of the gripframe under the stock, secures and pre-loads the hammer leaf spring - it is not an 'adjustment' leave it tight!
My 625JM was great as-delivered - and only slightly improved after break-in with the spring change. I have had a couple of ftf's even with the Federals, but the gun was dirty - and so were the moonclips. They have all gone boom the second time, however. Any separation of the clip from the cylinder back/ejector star is liable to cause the primer to misfire, as some of it's energy is used in pushing the combo home. This can be caused by crud on the moonclip, a warped moonclip, or crud under the ejector star - particularly where the ejector rod atteaches - clean carefully. I like the nylon bristle M16 style brushes or my wife's toothbrush, depending on my mood. I soak the moonclips in lacquer thinner to remove the crud.
BTW - I love the stocks - mine look like plain Jane walnut, yours look like pao ferro - really nice. If you want a HiViz front sight, it takes the same one as the 629 classic with the spring-loaded sight mount - $35 from S&W. Have fun!
John ( aka Stainz)