Nope just buy used and know what the dash number represent.
I hope this helps.
For the S&W 686;
686 (1980) begin prod.
686-1 (1986) radius stud package; floating hand
686-M (1987) recall by S&W & overstamp to indicate mod. (applies to 686 & 686-1 only)
686-2(1987) change hammer nose
686-3 (1988) new yoke retention system
686-4 (1993) change rear sight leaf, drill & tap frame, change extractor, introduce Hogue grips
686-5 (1997) change frame design to eliminate cylinder stop stud, eliminate serrated tangs, change to MIM hammer & floating firing pin, change to MIM trigger, change internal lockwork
686-6 (2001) internal hammer & trigger key lock
686-7 (2002) performance center variation in 38 Super introduced