If you've ever tried riding somewhere with a heavy backpack, you can appreciate the practicality of having a rear rack to carry stuff.
When I built my bike years ago, I used cheap second-hand racks made of steel, and all of them broke under regular commuting use. So I went about finding a proper replacement, and stumbled upon the Axiom Journey rear rack.
The rack itself is made of welded aluminum tubing. It's surprisingly light for how strong it is, as it's rated for 150 pounds and only weighs 1.5 pounds! Believe me when I say this thing is beefy. The most I've carried on it is about 80 pounds.... one of my kids rode sitting on it with no problems. I'll just say my rear wheel would probably blow spokes before the rack breaks.
On most 26" or 700C bikes, installation is fairly straightforward, assuming you have rack bosses on the rear seatstays. Instead of a flimsy piece of sheetmetal, the rack is held with two aluminum tubes (the same as the rest of the rack) mounted in solid metal blocks. If your rack bosses are lower down, you may have to cut the tubes to get them to pivot downwards enough. For my bike, they worked fine out the box.
There's a bracket to mount a standard rear tail light, which didn't fit my homemade light. It was easily replaceable, though.
My pannier bags fit fine on the rack, but the rack tubes are a bit larger than some, so make sure your pannier hooks are seated on them firmly. I especially love the rear "wing" tubes that keep the panniers from getting sucked into the rear wheel. They are very effective, and (I think) necessary.
If I had to find something to dislike about the Axiom Journey, it would be the weirdly-shaped top platform. I'm not really sure why they shaped it that way. A medium trunk bag kind of dips in the middle, as the flat part is below the side tubing, until it curves up in the front and back. The skateboard-shaped deck is pretty good for keeping backpacks and soft bags from sliding front or back, I suppose. It's never caused a real problem I guess, I just don't understand it.
Also, the tubing crosses the top so that your pannier hooks may force you to slide them to the front or rear, but again, the deck is big enough to slide them all the way to the rear to prevent heel strike.
Overall, I can't imagine spending more money for a rack that carries less than the Journey. It's a workhorse, perfect for touring and commuters who just want something that works without breaking. Granted, if you're touring out in the middle of nowhere and it does break, finding an aluminum welder might be a challenge. But for commuting, it's perfect.