Any old vacuum will pick up pet hair. Pet hair sits on the surface. You need to find one that deep cleans your carpet. Everyone is going to have their preferences.
I have a Eureka (yes, a high-end one). It's not bagless - I hate bagless. I've watched various people in my family try nearly every bagless vacuum brand out there and no one likes what they have, including Dyson. I've had my vacuum for seven years now, and have only changed the belt once. It's easy to fix when your kid vacuums something up that she wasn't supposed to. All the attachments are onboard, so it's not an inconvenience to vacuum the edges of the carpet a couple times a week too.
I had to use it at work once because our store's vacuum broke and apparently our replacement was on backorder. I couldn't handle the floors being dirty so I brought mine in. It worked so well that it pulled the carpet squares up and I had to reglue a few high traffic areas.
The only thing I don't like is that I go through vacuum bags like mad. We vacuum every day since we have three cats and one bag lasts about three weeks. There is a noticeable difference in effectiveness when the bag is close to full so when it seems like it's not working well, it probably just needs a new bag.