Regarding the Alessi holster shown in post #3, the shoulder harness is significantly different compared with the Bianchi 9R2. The 9R2 has a wide leather shoulder strap supporting the holster with tension fitting being done with approximately .5-inch elastic webbing.

The Alessi's harness appears to have no elastic webbing to act as tension fitting. Rather support seems to be shared by both shoulders that are connected by a wide leather strap.

I anticipate there are several other types of harnesses, more likely to be similar to Alessi's than 9R2's. It probably makes little difference when holstering a sub-20 ounce revolver. But when the revolver/semiautomatic has an unloaded weight over 30 ounces, supporting that weight for hours at a time without neck ache becomes about as important as the handgun.

Among harnesses for shoulder holsters, what methods and/or specific harnesses offer exceptional comfortable support for heavier handguns?