I do psychology and sociology, both AQA.
I find psychology assessments easier because there's more short answer questions and they can ask similar questions over the years so if you do enough exam questions you could memorise some answers, especially with research methods. Whereas with sociology there are longer essay questions and there's a broad range of topics they can ask about meaning you need to practise essay skills as well as being confident in the content.
However I find sociology easier to revise than psychology. For psychology there's a lot of content to remember in the form of case studies and also evaluation of these case studies which can go into a lot of depth, and it can be easy to get psychologists names/statistics/etc muddled up. With sociology, there's a lot more sociologists names to remember + what they did/found, however these can be easy to remember if you do active recall (I recommend anki).
In terms of content, both subjects are content heavy. With psychology the subtopics are smaller, however with sociology there are subtopics within subtopics (eg I do Family which is a subtopic, and in this we have childcare, demography, couples etc.). Of course this will differ with exam boards.
I enjoy both subjects but I prefer psychology, just due to personal preference.