I only did psychology but in quick summary...
Psychology has a fairly straight forward exam (Questions very tight to the specification)
Technique slightly tedious, but more than manageable
Quite memory exhaustive - expect to spend a lot of time revising the topics.
Basically if you put the time in, you can walk out with a good grade (plus Psycho is a pretty popular A level, so theres lots of resources and help on TSR/web).
Depends what you want to do in the future i suppose too