I have never tried C-Thru, but like a few other posters, Prrr was my first MAC purchase. I saw it was used on Mandy Moore in her "Cry" music video and I loved her lips in that video. I liked it back when I used to use it, but I kind of dropped those shades for reds and hot pinks. One of my old boyfriends hated whenever I would wear it. Although he said it looked amazing, he didn't like the fact that I wouldn't let him kiss me when I had it on. I didn't want to ruin the color! lol