I'm 6ft and found it ok as long as it's not too heavy,it was more comfortable when i used it with pouches
The adjustment straps are a bit lacking especially in the shoulder area!
I sold a Long back DPM PLCE bergen and bought a snugpack rocket used it for a few months I then sold the snugpak Rocket and bought (and have been using ever since) short back OG PLCE bergen.
I prefer the PLCE by far but it's not as comfy.
(I suggest you try both! or at least the Karrimor version!)