Well, it depends on the DVD... I think the hardest one is the Gambling DVD, which im working on right now... For some sleights you will spend months (i.e. his in the hands false riffle shuffle, which btw i still cant do
), and some will take you only a few hours (i.e. false table cut). So it really depends on your skill, and how fast can you learn this kinds of stuff...
I think it is the same difficulty as Trilogy...