I started out hopeless and resorted to using faces from the ME2 Faces database, but eventually got the hang of the CC and created one that I was very, very pleased with and that I consider "mine." She is smoking hot in the first game, looks pretty much the same but a bit "sharper" in the second game, and then in the demo I went "holy crap, who the hell is that?" I've fiddled with the sliders trying to recreate her, but she still looks scary - perhaps because all of the eyes (for FemShep anyway) just seem off. I like the hairstyles just fine and think they did an especially good job revamping the various bun/pulled back styles. But the eyes are these sort of bizarre painted-on mannequin eyes, with poorly-defined edges. Even the no-makeup eyes were well-defined in previous games.
My FemShep also looks rougher and older, but I don't have a problem with that. After being rebuilt from what looked like a used fireplace log, I wouldn't expect her to look fresh from the blender anyway. (Cerberus did rebuild her; they did not clone her, so I'd expect her to look worse afterwards rather than better as some seem to.) I was worried that Bioware had turned FemShep into a pouty teenager, which is what the new default concept art suggested, but my worries there have been alleviated.
I haven't tried recreating my ManShep yet, so can't comment on the quality of that transfer.
I realize that some might consider this a minor issue, but it would be disappointing if I don't see "my" familiar face in ME3. Then again, I'm someone who started ME over again about 20 times because my original CC creations all came out looking like Michael Jackson (after all the surgery) no matter what I did, and I just couldn't stand looking at them during dialogue scenes.