I'd not rush out and try to find the latest revision of the parts just for the supposed advantage of a "tactile reset".
Yes, the nice thing about the latest slide stop assembly revision is that it can help provide for some added inward pressure on the TB, to help the TB tail more briskly reset under the sear nose, and without having to add more parts, but I'd not think it's going to mean there's a dramatic difference in each and every gun.
I was inspecting a brand new production 9c for one of the guys, and even though his 9c has all the latest parts revisions my 2010 production 40c has a distinctly more noticeable "tactile reset" (and it's a stock gun). I don't notice it when shooting - as I shoot to trigger
recovery, not
reset - but he certainly did when I let him try it. He was very disappointed that his latest M&P didn't have a very noticeable "tactile reset".
Of course, once he was using his new 9c for a fast-paced qual course-of-fire he managed to short stroke the trigger because he was trying to hold it back to the "reset point", instead of letting it properly recover. At least he didn't experience the other type of problem that keeping a finger on the trigger under stress can cause, searching to find the reset point under stress, which is an unintentional subsequent shot. (These are often caused by the trigger being rocked under recoil, or by an unintentional muscle tremor or flinch, while the trigger is staged at the reset point. Not good at all.)
I worked with him on some more demanding drills and got him working on shooting to trigger
recovery, getting his finger off the trigger so it could fully recover between intentional shots. His times quickly went down (although he wasn't aware of it, at first) ... his scores went up as his accuracy improved ... and halfway through the drills exercise he realized he wasn't feeling the travel distance, weight or "smoothness" of the trigger press. He was just functioning the trigger as needed, and was concentrating on making solid hits under stress.
Of course, some of the drills involved shooting while moving, shooting from new, different positions and postures and not being able to "index" his shooting arm during 1-handed close quarters reactions, so he had his hands full and wasn't as easily distracted by trying to distinguish the subtle nuances of "trigger reset".
Then again, he's a working reserve and has a CCW, so his primary focus isn't leisurely target shooting, but dedicated defense shooting.