I bought the Hoover Fusion(U5180) last December, and am THRILLED with it!! On the downside, it's sold exclusively at Walmart (don't hate me because I shop there), but on the plus side, it is very reasonably priced at $128.88. I questioned whether it would be any good for such a low price, but it just keeps amazing me. It's an imitation of Dyson, and claims it also "never loses suction". In fact, it claims it can even outsuction Dyson! It's not just a bagless, it vacuums via cyclonic filtration. Yes, emptying can be a bit messy until you get a good system down, but there are no filters to ever replace on it. You just rinse them off every so often.
I live in a very small 550 sq.ft. apartment with two very hairy cats. This vacuum has no problems finding hair when I thought there was no more hair to be found!
This was a replacement vacuum to my 11+ year old Kenmore canister which I also loved immensely, it just wasn't doing the best job anymore. I can't complain, it served me well for many years. Several of my friends also own or have owned Kenmore canisters, and they all have equally loved them as well. Not one bad word ever spoken about them. Can't say the same for their uprights, however.
Good luck, Jinx