BLUF: based on your needs, I would get a 4" 686.
I have always been a fan of S&W revolvers and own more than my fair share.
My 686 is a 6" gun I bought new in 1989 and it was made before they started installing those goofy locks. Additionally, the fit, finish, and trigger are all superb... Bottom line, it has the quality I expect from a S&W revolver.
I picked the 6" tube for use in the hunting field. If I were picking it for general use I would get the 4" model. Although revolvers are big and clunky when compared to the current crop of suitable semi-auto choices, if picking it for carry I would opt for the 7 round 3" model.
Fast forward to today. Over the last few years I've owned four new S&W J-framed snubbies and I've determined the Quality Control shop has been asleep up in Springfield, MA.
Three of those guns had to make trips back for repairs. Two had to be replaced as they were deemed "unrepairable". One, a Pro Series 640, has made four trips back to fix glaring fit and finish issues as well as to receive two new barrels. This on a Pro Series gun... OUCH!! They did fix it. Now it actually sends bullets where the sights point and all of the parts stay attached during the process!
I'm still partial to the look and feel of a S&W wheel gun. However, look it over closely for fit and finish issues before you purchase. One thing in the recent past is canted or "clocked" barrels.
Let us know what you choose.
Edmo