I just sat for A level physics this jan (both as & a2) & have to say i was lucky coz this time it wasnt as tough as phy normally is!
I guess the toughest topic in A2 comes from unit 4 (to some unit 6 synthesis materials such as accelerators & detectors are very daunting). To me it was the wave-particle duality when applied to hydrogen atoms (stationary wave pattern) & electrons (electron diffraction),spectra (esp emission spectrum) & some boring topics from expanding universe such as critical density. The main difficulty with a2 phy (mine was edexcel) is that u are expected to remember a hell lot of topics & apply them at different parts of the same question.When u are giving unit 6, u are to remember all other units (except unit3) for all parts of the paper.That demands a lot.keep practising a lot.thats the proven way for success.& it seems like may 06 paper's gonna be tough!
Good Luck!