I've had my Allbirds for a while and they are my go-to comfort shoe. I chose the natural grey/light grey sole which is one of their always-available options, which also include an all black and all white option. At the time of writing Allbirds is also offering a few limited edition colors including an Olive, Birch (very light gray or beige), Moss (green), and plum (my wife said this was "mauve").
The shoes are made of a premium textile made of merino wool from New Zealand. Wool naturally wicks away moisture, regulates temperature, and helps prevent food odor. After nearly a year of wearing these shoes (sockless, otherwise you risk shocking every metallic object you encounter) they did start to smell a bit. Once I noticed the accumulation of odor I followed their care guide for cleaning the shoes in the washer. One wash later, and their as good as new and I haven't needed to wash them since. The part of the shoe that typically starts to smell is insole, and if you have particularly smelly tootsies you can order some [replacement insoles] for a reasonable $25.
What first inspired me to buy these shoes was not only the look of sublime comfort or minimalist design, but the thing that got my to pull the trigger was actually the company's commitment to sustainability and transparency. The company only uses ZQ Certified wool, which means that no animals were harmed in sheering process. This wool requires 60% less energy to produce a shoe than typical materials. Even the insoles are made of sustainable materials, with castor beans being a primary material used. Most importantly, Allbirds is a [Soles4Souls] partner and they donate shoes to communities in need.
While these shoes are called "Wool Runners", I'm not sure I would recommend wearing them to run, particularly long distances. However, they are so comfortable, you may just have trouble taking them off.