I have fine hair, medium thickness, and so I decided to buy the Small Extra brush containing only boar bristles. This purchase was a big leap, especially because I've tried boar bristle brushes from the drugstore in the past and did not like them. I'm sensitive to smells and always felt they imparted a wet pig smell to my hair, no matter how stringently I avoided getting them wet, but that has not been an issue with this brush (the only smell I get from it is the rubber pad, which is not bothersome and does not transfer to my hair). The brush arrived very quickly, in a sturdy cardboard box. I've only been using the brush for about a week now, and already feel there is improvement to the condition of my hair. For years I've been frustrated by how oily my second-day hair is at the scalp, and was impressed to see from the first brushing that the brush was, indeed, drawing the oil downward as I brushed. I've noticed it can make my hair look VERY greasy at first, but after an hour or so it seems the oil gets absorbed and it is no longer noticeable. I completely agree with so many other reviews that say this brush gives a lovely scalp massage. My almost-three-year-old seems to agree as well; I tried it on her and now every time I comb her hair to detangle, she says "We can use Mommy's brush after!" She usually hates getting her hair combed and it's nice to get this unexpected side benefit of a toddler who's suddenly tolerant to getting her hair detangled!