As a mom of 4 who has read both the books mentioned *and* watches the Nanny shows, IMO it's really a matter of using the salad bar philosophy and finding what works for your individual children. Unfortunately, I've found that no one philosophy really covers the needs of all my kids. They are distinct personalities with distinct needs. I'm not running a large corporation with inflexible policies, so I pick and choose what works best from different parenting ideologies.
We always try to let our children experience the natural consequences of their actions, but at times the natural consequence is a punishment from Mom or Dad. For some kids, it helps to see their punishment and rewards laid out before them (perhaps they are visual learners?), some children need a goal to help them focus their energies, some children are laid back and just go with the flow w/out needing any sort of manipulatives. I personally find that applying *any* philosophy strictly, with no bending or compromising, to be counterproductive. So, if someone feels that charts work for them, great. If they don't, great. It's not a matter of laissez-faire, but a matter of not making someone feel like they are "doing it wrong" if they don't strictly adhere to one particular philosophy in all aspects of their life. JMO
Personally, I found "Siblings W/out Rivalry" to be useless. I've read it 3 or 4 times hoping for some light to click on. But, with 4 children and 5 years from the oldest to the youngest, I just can't make it work. So, I continue to explore different ideas, keep on talking to my kids and just hope for the best.
So, to the OP, I'm sorry I don't have any really concete advice. Just keep exploring, keep trying.