30 days till Mexico = time to start the 30 Day Shred

I've been meaning to go on a proper Mexico diet for the last couple of months and now with a month to go, I've got to get to it!  I've heard lots of good things about the 30 Day Shred, although I've also heard that it's incredibly hard going.  I'm planning on starting it tonight after I've downloaded it on iTunes - I know I can get it cheaper from Amazon but if I'm going to start it today then I'll have to download it instead, and I figured it's best to start when I have the motivation!  I'm hoping that blogging about it will make sure I stick to it - are any of you doing it too?  How are you finding it?