Q u o t e: the way i see it, theres 1 difference in high and low level capping.
Smoother transition between zones and areas, but with a requirement of putting all your skill points into few skills, to be able to survive.
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.
i dont think it is cut and dry like that.
the amount of skill points and how many skills used is more related to level cap on skills not player level.
and they can still make each area noticeably more difficult with a high level cap. you'll just have to level up three times instead of one. except you might actually feel like you were getting somewhere along the way.
or they could take a low level cap and make a smooth transition, but when you level up the game will seem to get easier for a little while, just like when you find a decent weapon in D2.
come to think of it, im not sure what benefits each level will bring besides a skill point and stats. i think as long as there is always some way to better your character other than random drops it will be ok. and skilled players most likely finish the game before max level anyway.