what do you think is better?

Apples and oranges, you really cant compare these 2 tricks as they are so different.

Well...you can compare the overall strength and impact of the two effects. IMHO, Cardiographic is a much stronger effect that a standard newspaper tear; it combines a bit of "mentalism" with a card rise and leaves a spectator with an "impossible souvenir." In fact, I perform Cardiographic...but I don't perform a newspaper tear. Having said that, there are a lot of very good newspaper tears, and if I was going to do a one, I'd probably do Gene Anderson's.

Bear in mind that, in the hands of a mediocre magician, both of these effects have the potential to fall flat and look like total crap. Cardiographic will require much more work to get to performance readiness than a newspaper tear, though.

FYI, I built my own Cardiographic; if you are handy, I'd recommend doing the same. Buy Martin Lewis's "Making Magic" DVD set; he teaches you how to build and perform your own Cardiographic, as well as many great effects. The DVD and the supplies for the Cardigraphic will cost considerably less than purchasing a pre-made Cardiographic; as well, building it on your own wll give you a better appreciation for the working of the effect and ensure that it fits you properly.