720 is a big gamble. You can't really count not knowing what to expect in the equation of how good a move is because that's more about the player not knowing the information than the move itself. If you're evaluating a move you should be looking at it as if everyone knows what they're doing. If it's STILL good then you know you have something serious on your hands.
For command grabs, you just have to jump. If you're even a pixel off the ground you will be safe, so if Tager goes for a 720 he has to hope you aren't jumping or he just wasted 50 heat and is probably going to get combo'd.
But yeah, Tager and Hakumen have always been real good when everybody is just learning the game because they can deal out huge damage with a few moves. But once you go up the ladder it loses its effectiveness.