I have heard that it is not as good of a workout because the weight is applied incrementally. The closer to the body you pull, the harder it is. It is better for strength building and cut to have the muscles working as evenly as possible throughout the movement. (This applies to BowFlex, since I don't even know what the other one is.)
I have a friends wife who is a Bowflex ADDICT---the only drawback I see is you have to manually switch the rods where some other machines have a lever you simply move, and let me tell you it has entirely worked for her, someone who hasnt worked out in 20 years---she has completely changed her physique...