It's honestly up to you.
I find the DC65 to be an annoying vacuum to clean with that has mediocre suction, but if you're are used to a DC07's suction then you'll be fine with the DC65's.
I personally think a bagged machine would match requirements better, but if you are truly a Dyson lover, this advice will fall on deaf ears.
I will say that I am impressed with the DC65's hardfloor cleaning, but my Rainbow still beats it every time.
The DC65 moves fairly well, though the whole ball technology is not my cup of tea.
Go to Best Buy and try one out. If you fall in love with it, buy it.
The best advice I've heard is: "The best vacuum is the one the person will use."
There is no point for you to buy a Kirby if you aren't going to use it. If you will use a Dyson DC65, buy it.
A good example is my grandfather. He has a Hoover Z (show here
http://www.lasplash.com/uploads//1/pair-_2__002.png ) and uses it every other day. When he had a Kirby Heritage, he was vacuuming maybe once a month.
EDIT:
Also, I dread the day someone asks me to clean the cyclones of a DC65. Talk about over-engineering.