I tend to agree that I don't think the system is that complicated or that the signs are unclear, though I would support any campaign to make them clearer. Also, given that it will mainly be locals who use it, those who have been "stung once" are unlikely to make the same mistake again.

I would say that it is always a pain when the machine (not under cover) is not working as there is only one other machine (under cover), don't see why they can't institute a 'register by phone' system like most other parking in London.