DM, perhaps you would like to detail how much bigger the cabin in a 189 is than a 139 then!
What is so disappointing is that AW had the opportunity of creating the de facto SAR helicopter but they couldn't understand the concept that the important working area in a SAR helo is the cabin, not the cockpit. If they had just increased the height of the cabin from 1.4m to 2m and left all the other structures pretty much the same, everyone would have been fawning over it and bought it worldwide.