Yes. Quite a lot of it. Started it like many, having read Born to Run and was inspired by it. Also, I would get to 7 or 8 miles and get very painful knees.
My running gait has changed completely as a result of BFing and I can now run comfortably for 20 - 30 miles, on or off road, but much prefer off road stuff. The main difference is that running BF is a very liberating and joyous experience, and without wanting to sound like some long haired hippy, a very holistic experience.
There are many people jumping on the BFing bandwagon, specifically (if it's not an oxymoron) the shoe manufacturing companies. New Balance, Innov8, VFF and Nike to name but a few. All of these talk of 'transitioning' to BF or minimalist running. They are all trying to sell shoes that supposedly aid the change to forefoot style running via incrementally reducing the drop from heel to forefoot.
Their solutions are slow, expensive and NOT barefoot.
The best advice I could give is to start running absolutely barefoot on a hard surface. City roads and pavements are by far the best surface to learn technique. Urban pavement is generally smooth tarmac rather than tar and chip (very uncomfortable) like many rural roads. Dirt tracks and grass are great to run on but do not promote good BF technique. Also, I do not run BF on the grass in urban parks because of the risk of hidden sharp items that you would see on a road or path.
But a STRONG word of advice. You should be very patient learning to BF. Shod running does not promote strength in the foot. The bones, tendons and ligaments in your foot will be atrophied because they will have had very little exercise to date. The good news is, that the foot evolved to move unshod, and with some care and exercise it will strengthen remarkably quickly.
A good approach to starting BF running can be likened to beginning to run completely. Start by taking off shoes and socks and jogging a couple of hundred meters or so. No more. Do this for a couple of days then slowly and gently start to build up distance. Don't think about speed, just form (below). Why? As I mentioned above you are beginning to condition your feet, Achilles tendon and legs (especially your calf muscles). Your Achillies and calf muscles will become very stiff and sore initially. Don't over do it at this stage. Remember, it's your body sending you a message. BF running is all about feedback, so just start getting used to what your body is telling. After some time (depends on you), you will feel relaxed and just end up running BF over considerable distance with very little effort and a huge deal of satisfaction.
There are loads of web resources about technique, so I will just tell you what I find useful as pointers.
1. Relax when you run.
2. Run with slightly bent knees. They are part of your shock absorbing system.
3. Don't reach out with your front (leading) in each stride. When it lands, it should hot have any forward motion. It is effectively just place on the ground momentarily to support your weight as you move over it. You'll know if you've got it wrong because you will get hot spots or blisters.
4. I find a 'good rule of thumb' is if you can see your feet when you are running you're stride is too long. Each step should have the same feel as a gentle hop on the spot.
5. BF running is not running on the balls of your feet, it's forefoot running. I find that my heels do touch the ground, but towards the end of my stride, just as the take off phase begins. If you have any impact on your heels (which you'll know because it hurts) you need to shorten your stride.
6. You will find that naturally, you pick your back foot up higher behind you as you are in 'flight'.
The other thing to remember as you get used to BFing, is that the nerves in your feet will begin to be stimulated. There are about as many nerves in the feet as hands and very quickly you will begin to feel textures and detail of the surfaces you run over. In a very short time, you will notice that your stride, gait and cadence will change as you move from on surface to the next. However, it is very easy initially to interpret these sensations as pain. This is because your brain does not understand how to interpret these new inputs. Just bear in mind that the foot and it's skin evolved to stand on all sorts of surfaces. It's much tougher than you'd imagine. The other thing that you will find is that the skin on the soles of your feet does not get hard. If anything it gets softer but slightly thicker. It's weird but that's how it is.
People often ask what happens when you step on something sharp or 'unpleasant'? Quite simply, you become far more aware of the surface(s) you are running over and use your eyes for very accurate foot placement. It's the same as picking a line down a rough piece of track on a bike. You just don't really think about it.
If you choose to learn to BF run in shoes, you will not get the benefit of all the feedback you get from perfect interface with the ground, and not feel the full effect of changing your running style.
I'm not a BF evangelist and do use natural style shoes in addition to BFing. I tend to run in shoes during the winter, because, a) it's cold; b) barefeet don't grip well in wet mud.
Enjoy, but take it easy to begin with.