Well let me be the bad guy and say that in the heat of battle. For 99% of the Cowboy Shooters an ultra slick action is NOT going to win matches. There are many other things you can do to improve your stage speed mostly practice, thinking about how to run the stage, and watching the fast guys. OH yea don't do anything dumb. I have several different Rugers I have shot in matches with great success with nothing more than a Wolfe Spring Kit in them. Not much you can do to an Old Army except put in an 17# main spring for one and dry fire with the nipples out of it. Same goes for my Marlin and Ubertie Rifles. Uberties a Short stroke kit and lighter springs. Several videos on how to slick up a Marlin and get rid of the Marlin JAM. I have done all the required work on my stuff which is very easy to do.
About the only time a real slick action means anything is when you let your Pard feel how slick it is. I have a couple of 3 screws that are pretty slick after quite a few 1000 rounds and a spring kit.
Save your money and do the only work needed yourself.
Jim makes an EXCELLENT point. Lots of practice,, combined with a quality firearm, and working on techniques that improve your skills, will be MUCH better than having the slickest gun there is.
I recall the day a good friend (and LEO) whom I was the RO for at a USPSA match. He was being told he needed "xyz" type of gun & equipment. Well, he blistered the stage. Later,, when the match was over,, I suggested he demonstrate SKILL. I was on the timer, and I personally saw him do the following;
Facing the target, hands at surrender, target at 10 yds. He took a simple plain Kydex holster, and a totally stock Glock 9mm as his equipment.
At the signal, he drew & fired (2) rounds at the target. His (2) shots were touching each other, and the time was .62 of ONE SECOND.
He politely explained that he spent a lot of time practicing with normal equipment, because it was what he carried daily. Lots of dry fire practice, combined with live fire practice.
That said,, a good clean action job, where it removes burrs, allowing proper contact points with all the moving parts, can make careful long range accuracy better,, IF THE SHOOTER DOES HIS PART.
A good trigger in a smooth action,, (notice I didn't say light) can make serious long range accuracy handgunning easier to achieve.