You need to probably just define some requirements and go with it.
Some want the lightest possible rack, others want strength instead.,, most US cyclists avoid racks completely in favor of a small bag under the saddle, or strictly use their jerset pockets.
Some want full touring racks, others want something to just carry a trunk bag, or just carry panniers.
I use mine mostly for a trunk bag, and occasionally use panniers. I don't worry about weight, and like a large platform for my trunk bag. I currently use the Jandd Expedition Rack
Expedition Rack
If I had one additional feature, I would like an optional wider platform to enable me to easily mount a backpack on the rack for commuting. When I want to carry the backpack, I would like to be able to
quickly attach the additional platform and have it
securely hold my backpack using bungie cords or a cargo net.