Your Infinium matches the Whites for depth with a slow sweep. The J.W.Fisher's are bullit proof for the diver, very reliable, great performance but I think they stretch the truth on land use where their deep diving electronic design works against them.
You can excell for sensitivity on land or at depth in the water but not both.
As you want it for diving I would think it would be the best choice for you and it has far more performance than the 6x. Question is do you go for the bulkhead version at the extra cost ?