I own a 6-inch 686 myself, and it is a superb revolver. That being said the choice between a 4-inch barrel and a 6-inch barrel for a fellow of your circumstances is almost entirely a matter of esoteric preference.

For target shooting at a local or home range, the 6-inch gives me more hits in the bulls-eye.

For the utility of carrying in a holster, be it open or concealed carry, I prefer a shorter barrel.

For pure coolness and eye appeal, I vote for the 6-inch barrel.

FYI, I own and shoot a bunch of revolvers, including 1-7/8 inch snub nosed 38 specials, 8-inch 44 magnums, and just about everything in between. They are all beautiful to me and each is a different and enjoyable shooting experience.

Get whatever revolver that really jingles your bells!