Minimalist shoes, as they are more commonly known, are a very good balance between going barefoot and having some form of protection from weather and debris. I own several pairs myself, and much prefer them to the standard set of shoes that have soles thicker than an inch. Minimalist shoes are more comfortable by far, and are much better for your feet in the long run.
Now, to attempt to dispel any apprehension for the previous statement, let me make a few points. One: The human body has been developed to walk, run, and generally move in bare feet. Feet are meant to be strong. This is impossible if they are constantly confined to a cast in the form of a shoe. Shoes cause muscle atrophy and lead to fallen arches, weak knees/ankles, and back pain.
Two: Feet are a highly sensitive area. This does not mean they are easily injured, this means that they are incredibly important for understanding the world around us. When you have a quarter inch plus of rubber between your foot and the earth, you're not getting the sensory cues you should be.
Personally, I love minimalist shoes. If you're starting to get into going barefoot, they're a good medium to progress into it. But between those two choices, I'd have to go with actually being barefoot every time. Driving, walking, running, skating, indoors, outdoors. There really is no bad time (outside of construction zones) to be barefoot.
Barefoot shoes are made to feel like you don't have anything on your feet. A friend of mine has a pair and says they are the best shoes she has ever had. They fit the contour of her foot. They are also very comfortable as well as affordable. I think they work from what I have been told.
Barefoot shoes are designed to mimic running in bare feet, but running in bare feet is not a good idea because of injuries and because of wear and tear and weight on a person's joints. Barefoot shoes are just a trend that does not make sense. A person who runs should be wearing a very durable, supportive shoe.
Wearing a shoe that makes it feel like you are barefoot sounds like it could cause possible problems for your legs and feet further down the line. Shoes are built to support more than just our feet, and is for more than just comfort. It helps our legs, and muscles to keep from getting sore as well.
No, I do not believe that barefoot shoes work and are instead bad for your feet. I believe that barefoot shoes are also a scam, and are making Americans think that they are getting a bargain and better grade of shoe when they are really hurting their feet and causing pain they don't need.
My understanding of barefoot shoes is that they offer the closest running experience to barefoot, but protect one's feet. Running barefoot is not necessarily a good thing because a runner puts more than average wear and tear on their feet and limbs. Therefore, they need the support and cushion and athletic guard that a full-out running shoe offers.