Going 'barefoot ' is more energy efficient some studies have found, but those studies have been done with experienced runners.
My average patient is certainly not that, and I would count experienced runners as those that do over or above 25K per week.
Injuries caused are many, mostly to the mid foot from fractures, soft tissue injuries, shin splints, avulsion and tendonosis injuries..
These injuries can occur during any running activity for those new to the sport and experienced runners, but the injuries in clinic from those who have just taken up barefoot running, or had been diong so for some time and presented with different overuse injuries were very noticable.
But, if it works for you and others then carry on! but next time you are watching any sort of athletic race of distance, have a good look to see how many true forefoot runners you see.