Good question, Kristin.
The short answer is yes, I believe the Dyson is that good. That doesn't mean that others don't also do a very good job.
My personal conclusion is that almost all quality vacuum cleaners have reached the point where they all have powerful motors, which makes them effective, but some of them are too heavy as a result.
Recently I tried a Miele, another good brand which costs about the same. It was too heavy for me to want to use, but I'm pretty sure it cleaned at least almost as well as the Dyson. You just couldn't 'SEE' the dirt and debris without opening the compartment, so it wasn't so emotionally rewarding to lug it around. The Dyson isn't too heavy and it's so fun to look at. It looks MEAN!
I have a little 'stick' vacuum by Electro-Lux that charges, you remove the cord, and zip all over the house without having to bother with plugging in electric cords. The vacuum compartment detaches so you can clean stairs, window-sills (where ants have been coming in), and even your car. May not be as powerful, but is really handy. It's great for 'spur-of-the-moment' cleaning. That one obviously doesn't have the powerful motor that really sucks up allergens as the Dyson is supposed to do and appears to actually do very well.
The main FUN thing about the Dyson is that plastic see-through 'bin' where you can see all the dirt and debris that your Dyson sucked up. That is a selling point for me. It makes vacuuming seem more productive, because you get to see the fruits of your labor. It definitely did get dirt from my tile and hard-wood floors when I didn't think there was any dirt there.
It probably seems strange that I have so many vacuum cleaners and I'm still repairing my built-in. That's because I strongly believe that you repair the house when it needs it or else you'll soon have a house where everything is in disrepair.
The reason I have so many vacuum cleaners is that the manufacturers have sent them to me to use and give my opinion of them. They seem to think if you have a dozen, you can make better comparisons. They also must think that I like to vacuum a lot, which I don't...never will.