I was at the MAC counter a few weeks ago, and told the MA to pull out a full sized #190 (foundation brush), and #194 (concealer brush)...and he rec'd the new face brush set from Holiday...but I said I wanted the full-sized ones....The two MA's smiled at me knowingly and said "Yeah, the brush sets just aren't the same quality..". BUT they did add that the quality of this years' Holiday sets are LEAGUES better than of years past!
I laughed, 'cause the female MA was like "The regular brushes are hand-made, and get a lot of love. The brush sets get NO love!" LOL!!!!
Still, I think if you don't have (m)any MAC brushes, then the sets are a *great* way to go. In fact, I'm buying my sister (she has NO brushes at ALL) the face sets and the 'mixed' set this year for Christmas!