I have carried the 6" and 6 1/2" 629 when in bear country and the extra weight over the 4" is balanced by the fact it will hit harder. That is a comfort that out weights the extra discomfort of the weight difference between the 4" and 6" barrels. In small bear country or mountaim lion country I really like the SW 329 though I hate to fire it with my carry loads of Garretts.
Shoulder holsters IMO are not comfortable at all. A heavy contoured belt like Galco's and a close riding Roy Baker pancake holster is no problem for this average size guy.