I love using my MAC studio touch up concealer stick...it's SO convenient because you can basically color over your spot like using a crayon and just dab it a bit with your finger to blend...throw it in your purse for touch-ups to go!
i've tried both and i prefer mufe's concealer. it goes on really smooth and covers great. mac's worked fine for me when i first got it but it started to look cakey. plus mufe's shades match my skin tone a lot better.