fruitshoots I HATED 6W6P at first, it was the first Jillian DVD I tried (it was delivered before the shred), I got midway through the faster second half of the L1 and gave up in a temper. It was too fast.
However it is now one of my favourites. It is very hard at the beginning but it is brilliant how quickly you get used to it - now I much prefer L2 as it is more fun. It is very cardio-ey though, I have to be in the mood to do it. I think L2 of the shred and ripped are very cardio-ey as well. NMTZ is very relaxed.
Doing both levels of 6W6P back to back is very hard, this week I started with L2 so I didn't feel like killing myself during the moguls when I had already done 50mins of workouts. It is a lot easier to finish with the comparitively more chilled out L1.
It is worth a go, though. I was SHITE at all the DVDs when I started. They make you feel really fit and confident.
I am tempted to develop the obsession somewhat further and buy a multi region DVD player (they are only £25 on Amazon) and then I can get the ultimate shred, yoga meltdown (!) and the other DVDs they only sell in NTSC.
Oh dear. Perhaps I am the biggest loser. 