How good are cheet-sheets for test?

Hi,
I was just wondering how reliable the cheet-sheets/Troytec OCP docs are for the real tests....anyone have any experience with them as to whether they are a good guide for questions on the test? How are the STS exams then also? I know that the cheet-sheet/Troytec docs for MCSE are right on the money as long as you understand the answers (from actually trying it out or work experience) .... but it was absolutely a good investment to get those for the MCSE exams. Anyone have any thoughts?

Have heard nothing conclusive .. Anybody who wants to pitch in !!
What experience they have had with cheat sheets...they sure helped when
i was passing college ! what say you ?

cheers
HS