In which I take on a legend.
MAC 217 blending brush is a multi-use makeup tool. Domed shape, full and fluffy goat hair that blends and buffs everything from eye shadow to cream concealer, the 217 is a very popular makeup brush that has very little competition from other brands. Whoever was responsible for designing this classic MAC brush managed to strike the perfect balance between hair length and density, that makes the 217 so efficient.
MAC 217 has stiffer and shorter bristles than luxury blending brushes such as Chanel #12 or Edward Bess. It's not as soft and I wouldn't use it for an all over wash of color. I prefer using it for cream products such as Bobbi Brown Long Wear Cream Shadows, and as mentioned above, for concealer and even precise foundation touch ups. It's also great for blending different eye shadow textures together and cleaning fallout and other under-eye messes.
My older 217 brushes seem to have been holding their shape better than the two I bought over the last year. I'm not sure what MAC changed there- perhaps it's the hair quality. But even with the tendency for splaying (I dry them in little plastic tubes to coax them back into shape), this is a great brush that I use on a daily basis.
Bottom Line: a building block for every brush collection.
MAC 217 Blending Brush ($22.50) is available at the counters, MAC stores and online.