Oddly enough, I just had to make this decision. We had owned a dyson animal and it finally died. I did my research, did some informal polling of friends and decided to buy a shark (model nv752). We've had it for about 3 weeks now and I really like it. Super sucky (in a good way) and I like how the motor portion detaches so you can use the stick part to get under furniture, etc. The detachable part, used with the included tools, makes doing stairs very easy.

While I really liked our Dyson, the shark was hundreds cheaper, and so far is a very nice vacuum. We got ours from bed, bath, and beyond and with sale they had going on and a 20% discount (they send out coupons all the time), I saved $100 off the regular price. I felt like it was a pretty good deal