As long as you can keep in mind you're not seeing Max Maven in action here, you'll probably enjoy the simple effects available. Some of the mentalism offered is straightforward and plays well to a small group or even two individuals. The "ESP with Playing Cards" routine plays well for a layman audience, but it won't fool anyone with even a beginner's experience in magic until you get to the sandwich effect at the end. That pays off well, I'll admit.
"Flip Flop" is so complicated it almost confuses the spectator in the video. The "Hoy Book Test" and "Pick-A-Date" are old routines that are probably on several other videos out there (Ross Johnson's "Simply Psychic" has a better version of the book test that involves describing entire paragraphs rather than a single word, and the video costs half the price). To be fair, David's method does allow a certain impromptu handling if you're at a party and you know someone is going to ask you to do some magic for them.
"Grey Elephants in Denmark" really blew the audience away...in 1995 when Max Maven did it on "World's Greatest Magic". Unfortunately, since then it's been so over-used you can't even consider trying it any more. My 13 year old son came home from school trying to pull it on me because his friends had taught it to him. You might fool a few folks with it, but it's a risk.
"Jumbo 8 Card Brainwave" is probably one of the best effects on the video. It can be adapted for regular Poker size cards if you don't want to play it big for stage. His handling is good on it and for the effect it doesn't take much practice (one move is all you have to learn). He also does a couple of routines using ESP cards that you might consider. It should be mentioned that they can be adapted for use with regular playing cards if you tweak them a little. That would allow you to throw in a little mentalism in the middle of your card routine if you wanted to.
So all totaled we have one killer routine, two fairly good ones, two that can be tweaked to be useful, and four that probably shouldn't have been used. If you're just getting into mentalism, you might consider this, but if you have any experience with it you can skip it.