I've had my S&W 686 4" for about 20years and only work needed was a trigger job (not needed, but I wanted a really smooth trigger) and a S&W rep at the National Police shooting championship filed down the forcing cone just a bit because the cylinder was binding a bit on one part when I did a lot of firing with lead wadcutters and SWC during qualification drills. The reliability is great after that, but the ultimate accuracy decreased a little bit.
I've shot the Rugers only briefly, but understand that they are very sturdy guns. I have a Taurus 4" tracker .357 with the ported bbl, but don't like it nearly as much as my 686; it's just not the same level of quality, but is still a serviceable weapon and a bit less expensive.
Alchemist77