I would suggest that any product which claims you'll shred like John Petrucci on speed in 2 weeks is probably exaggerating. It will probably show you the same exercises that are available all over the net, they've just packaged them up and want paying for them....

With practice, you'll play faster, but I doubt the software would be drastically better than practicing the exercises. It might help if you need structure though - it'll guide you rather than you having to find your own way. If that is attractive to you, it might be worth a go...