I guess it depends on your wish for improvement, and what you can expect a spring kit to do for you. My recently purchased BH .45 is OK as is, because I ain't much of a shot anyway. The elderly .357 is better, but I don't shoot it better.
I guess we should start with does it have the old trigger / new trigger? I hate the new ones that can be "locked" many years ago I was an apprentice with a gunsmith named Jim Cordor who was in my eyes a great gunsmith. He beat into me that you did not have to "replace" parts in a gun for a wonderful trigger job. Lawyers and stupidity is why our firearms have crappy triggers. I will advise you to find a good gunsmith "old school" and without replacing a single spring will get the let off @ 2.5 to 4.0 without creep. I could go into the procedure but if you are not familiar with Sears and trigger lockup, let an old guy take the gun apart and lower the trigger pull without ruining your gun. FYI. It takes me an hour to do a trigger job on an old or new model Blackhawk, my favorite hunting handgun. Favorite? Old model 41 magnum 6.5