I'm not a believer in brands of brushes, a brush is a brush and all brands do the same thing!
However a friend recently got me a set of goat hair brushes as a thankyou gift for grooming for her at an event, and they are oh so soft and put such a great shine on my horses coat, highly recommended! The only hang up with them is I hate getting them dirty, so just save them to use at shows!
I am having a hard time finding a firm body brush for removing dried sweat after riding. I really want the hand strap and synthetic bristles in a FIRM brush. I can't seem to find one that is quality with synthetic bristles.
I might have to give in and get one of these natural fiber brushes.....but they are almost too stiff and I worry about the durability of the bristles:
When grooming, you want to look at the density of bristles - the space between the bristles indicates the size of dirt that it will let pass through. Start with a curry comb to work the mud and thick dirt out of the hair first. Then use a heavy bristled brush to work out the larger particles of dirt and dust, and work your way to a very soft brush (goat hair or equivalent) to get the fine shine.
Elbow grease is key!!! If you have the patience, look up the thing called "wisping" (I believe??) it's done with a hay or straw "rag" of sorts, and many grooms swear by it.
Keep your brushes clean, and remember that a healthy coat comes from the inside out, so if the horse is lacking in something nutritionally, its coat will suffer too.
Altho good grooming improves the health of the skin because of the massage effect, every once in a while I'll haul out the shop vac. Rather than tie the horse I'll hold the lead. My bay would turn almost blood bay when vacuumed, until the next time he rolled.
It's ALL fit and Elbow Grease. When woman brushed their hair 100 strokes/night it was to distribute the oils from the scalp down to the ends. The same is true with your horse. The more gentle brush strokes, the shinier the horse. IMHO that is why show horses shine more than backyard horses generally do--ALL of that extra grooming. =D