For 18 years, the 686/586 was my favorite revolver. To answer your question, the 686 is reliable, accurate, well fitted and finished, very pretty with its classic design. The trigger is the usual excellent S&W trigger. Love it.
However, after renting a GP100 at the West Edmonton Mall couple years ago, I bought one. Now it competes with my L-frames for range attention.
At this time, I only have a 686-3 bought used 8 years ago, and a 586-0. I shoot only 38 spl +P+ reloads through both. I felt the 686 loosen ever so slightly after shooting about 100 full load 357 magnums. It is still very tight, though. Yeah, I know S&W designed the L-frame to shoot 357 full time, but that is just my experience.
The GP100 begs for 357 mags.

Both seem to be very close in accuracy, with the GP edging out the 686 by a very small margin.
Trigger is much better in the 686, than the GP. I am used to both, so no biggie.