I have come to this quite late, and haven't read the book, though am thinking I may have to go out and get it now.
So far, I have been lucky with my children (7 and 3), they don't fight, physically, they do disagree, and I normally leave them to deal with it between them, if it seems to be getting out of hand I will intervene and try to make them both understand why the other is annoyed, so 'punishment' has never been needed in these situations, I don't know if it is because they are so different in personality that they don't clash or if it is the way I dealt with DD when Ds was born, and then DS has taken her lead, I am pregnant with no.3 so I'm sure I'll find out.
I do discipline mine with 'time outs' although they are not 'sent away' for being naughty, they are told to go and calm down and think about why what they did was wrong, there is no set time they have to be there, just until they can talk to me properly about it.
I also praise my children for things they do that are good, if we have been out for dinner for example I will thank them when we leave for being grown up and allowing me to enjoy the meal.
Children are children, they have a different understanding to us, and should be allowed to express it, a child having a tantrum is rarely actually 'naughty' just frustrated.
So IMO, there are times and places for 'praise/punishment' but it depends on how you use them. DD knows the rules and understands why they shouldn't be broken, she also knows if she wanst to discuss something with me, such as 'why' then she can do, and I will listen, DS isn't at that stage yet, but when he is told I'm not happy with his behaviour and I want him to go and calm down and think about why the first thing he says is 'you still love me, mummy angry but still love me' so I do think it is possibel to use such 'punishments' without making the child feel unloved.
Like I said though I haven't read the book so I only know what has been said on this thread.