Dysons are above-average cordless vacuums but I don't like that you have to hold down the trigger to keep it on and there are competitors that offer a lot more value at similar prices. The V8 is one of Dyson's better cordless vacuums that isn't too heavy.
The LG CordZero A907GMS and Samsung Jet 90 Complete are both $499 and come with 2 powerheads, 2 removable batteries, and a charging stand.
Just a warning batteries across all brands wear out in 3-5 years. So if you don't want to replace batteries I'd look for a corded vacuum.