I have a fantastic double harness made to my specification by a saddler in southport.
In my opinion far better quality than the moneymaker ,all hand stitched with not one rivet and cost me under £100.
I wore it at a wedding for almost 15 hours carrying 2 x D800 with 24-70 f2.8 and 70-200 f2.8 .
Over the years I've used many different strap configurations but now would not use anything else when using two cameras.