My experience of both skis are a couple of years old. I don't know how those skis have changed since (but for the new topsheet).
Both ski has a rather conservative shape and thus respond nicely to various techniques, including rather 'oldschool' tricks. both skis are versatile and swift, more ar ease on soft snow than on ice (not a great grip on both models).
I would say the main advantage of the 4800 is the weigth. It's a very light ski, probably great for touring or light skiers. I prefered the 8000, in moderately deep snow for obvious reasons, but on hardpack also. The edge grip of the 4800 was really very average and its stability at speed questionable. A good snappy ski for a ligthweigth intermediate, good in the bumps and in tight spaces.
I would say it depends of your weight and where you ski. But chances are you'll overpower it if you intend to push yourself harder.
I would also say that the whole legend line (4800/8000/8800) is getting a little old now and should evolve next year. If you intend to keep those 5 years, you may want to look somewhere else. Those are still nice skis, but I wouldn't pay full retail price for them in 2006.
Edit to say it breaks my heart to turn somebody away from a Dynastar... But I think there are better options.