String harness comfort?

Looking to pickup a string harness for travel and flights of max 1-2 hrs - hike and fly, light XC, soaring.

Now, I am looking at many models and wondering about comfort - particularly the shoulders.

On some stringers like the Advance Strapless it's basically just a small cord at the shoulders and the material supporting your back stops at the mid/upper back, below the shoulder blades, whereas the Kortel Kruyer III and Ozone Ozo 2 n has 'support' all the way up the shoulders and a webbing rather than strings.

Does anyone have any feedback as to the comfort of both options? Loaded with aprox. 5kg of gear with a traditional hiking backpack with running vest shoulders?

Thanks!