Hey,
I have the Dyson ball for about 2 years and its really good! Before Dyson I had one from Miele, which was not bad, but the filter bags were too expensive in the long run. I have 2 birds as pets, there comes a lot of dirt together, say 2-3 bags in a month, that is expensive to see year. That's the main reason why the purchase of a Dyson pays off for me.
As for its actual vacuuming performance, it's realy good, light AND powerful. I have to admit that I was a little concerned when I bought it but I I have to say my concerns were unfounded because this is an amazing vacuum cleaner and I love how light it is to carry around. I have not regretted the purchase.
You can read more about vacuum cleaners here:
https://www.geekwrapped.com/guides/best-vacuums-for-carpet-and-hardwood . On that site you will find a lot of tests and reviews from various brands. That may help you with the purchase decision.