On to the subject at hand: Barefoot Running.
Barefoot running can be used as a tool for gaining better running form, I'll give it that. But barefooting it in the "real world," whether on roads or trails, has it's hazards.
Even the Tarahumara tribesmen in the book, "Born to Run" wear hand-made Huaraches, constructed of car tire treads. While not "cushy," they still offer a large (1/2" thick rubber) degree of protection from rocks and "sharps" to the bottoms of the feet. Barefoot Ted, a character in the book, sustained somewhat "shredded" feet after 50-miles (on desert trails), while wearing his Vibram FiveFingers. And we've had local runners' break their little toes while wearing Vibram 5Fs on our rocky trails.
And then there's one of the main characters in the "Born to Run" book...Scott Jurek, arguably one of the best ultrarunners in the world...and he's a heel striker! Scott excels at both trail AND pavement ultramarathons. He helped with the design of his shoe of choice (the Cascadia), which is a "substantial," and fairly heavy and cushy shoe, by any means of measurement.
Can a person run on rocky trails, while unshod?
There is one local runner that (I think) has the form, speed, and relative lightness to run barefoot on rocky trails fairly successfully...and that is "Barefoot" Josh Snellink. While I've seen him injure and bloody himself a time or two, he has a "realistic view" of what is possible with barefoot running (IMHO), and when it makes sense to wear shoes, to prevent injury or frostbite. For Josh to run absolutely barefoot on our local rocky trails, he needs to be obsessively observant of trail conditions, but he also needs to slow down on the downhills. This guy is no slouch...if he were wearing some type shoes and could run at his normal and (beautiful to watch) fluid pace - even on the descents, I think he would cruise to victory in quite a few races.
Where am I leading with all of this? Barefoot running can be a means to an end to improve your running form. It can also make you more aware of your body in relation to its surroundings. But, in the long run (pun intended), you will probably still need to have your feet shod, at some time or in some capacity. This is especially true for snowy/icy weather conditions, and rocks and "sharps" protection on the trails and roads. And, if you want to go faster in a race, you should probably be shod. Find out what's right for you, whether it's a pair of super-light 3.8 oz Universe, or a pair tire tread huaraches. And if you're not having issues while still wearing your "normal" running shoes, then don't fix what ain't broke.