the way i see it, theres 1 difference in high and low level capping.
High:
Smoother transition between zones and areas, but with a requirement of putting all your skill points into few skills, to be able to survive.
Low:
Noticable changes in difficulty when you enter a new area, but you wont need to max out skills to be able to kill. allowing you to focus on a more wide spec, and customize your character more.