yy I agree it's horrendously complicated.
As we have it at the moment though, there is horrendous resentment, because there are seen to be 3 'classes' (bad word, but ykwim) of people - the 'people on benefits', the 'workers who pay for everything' and the 'super-rich'.
And obviously, this is not correct, because, for example, in group 1, you have people who are in low paid jobs, people who cannot work through disability, people who are carers etc. In group 2 you have a huge variation (often because of geography) in terms of disposable income, and in group 3, who are often derided as 'fatcats', you have some bankers, some business people, and then people like JK Rowling....
But it is definitely true that there ARE people who milk the system, both at the top and the bottom. And I think the basic premise that IDS put across is a good one - that if you are able to work, it should pay you to do so. How you define 'able to work' is a whole different kettle of fish.