By themself (without any scalp hair), it would be difficult to create adequate and natural coverage on NW6 and above. I think both Dr Arvind and Dr Umar have cases where they have done so. The end result is always better when mixed with a fair amount of scalp hair.
I agree and disagree with some of the recent statements regarding the comparison of beard and body hair to scalp hair. First of all, some body hair does grow in multiples. In my personal case, I had about 45% or so of doubles or triples extracted. Where body hair falls short (so to speak) is in length. This is very true when dealing with forearm and leg hair. Your expectations for how long that hair will grow should be for it to grow exactly the same length it did in it’s original location. Quite often the hair will grow longer on the scalp than on the body, but one shouldn’t expect that.
For Beard hair, I’ve had 2 sessions that utilized beard hair. I used beard hair in my strip scars only in my last visit to Dr Arvind in December 2006. Beard hair is thicker and slightly darker. The hair grew in nicely and helped change the texture of the scar tissue somewhat. I went to Dr Umar in December of 2007 and am coming up on 5 months (hair coming in nicely). I believe I had around 1,200 beard hairs extracted with a couple hundred going into strip scars. The remaining beard hair was placed on the top of my scalp. I was going to do a session of only 500 beard hair, but opted for higher numbers after cutting samples from my strip scars and comparing it to my scalp hair. This link shows the comparison.
The beard hair come in mainly singles, but some have doubles and even triples (rare, but I know I had at least one in my initial trial of 13 hairs at Dr Arvind’s place).
For me a single beard hair graft provides the same coverage (in my case fine hair) of a 2-3 hair scalp graft. It also grows at same rate (little faster I think) and length of scalp hair. It does feel slightly different to the touch of my hand, but not distinguishable to the eye. The beard hair adds noticeable volume to the hair I have in bald areas. I think it best to try and transplant hairs that are NOT grey as the darker hair is hardly discernible, but the grey hair can sometimes stand out. Sure you can dye it, but IMHO it’d be better if you didn’t have to do that. They will most likely grey at some point anyway. At my age (just turned 50), not that big a deal. BTW, I’ve always thought it nonsense when I hear people say that I just want to keep my hair until I’m 40 and then I won’t care.
Here are a couple links to examples of grey beard hair. First is a patient of Dr Umar’s and second is a patient of Dr Arvind’s. I don’t believe you notice the dark beard hairs, but your eyes are immediately drawn to the grey hair contrast.