Well I have been using steel finger picks for about 25 years. Recently I have grown my nails long with the intention of picking the guitar but I have to say that the quality of sound that you get does not match in any way what is achieveable with metal picks. Maybe its because the nails are soft in comparison with picks.. I dont know.. but I only do the odd song using my nails. I take calcium tablets too.. it does seem to strengthen the nails.