Best exam board for A level Biology, Chemistry, Physics and Psychology

Hi everyone, hope you are doing well. I am currently at 6th form in my first year studying biology, chemistry, physics and psychology. Although these are now according to the new specification, you can still do an AS in them... it's just that it will not count towards the A2 grade.
I just want to know from someone who is familiar with all the exam boards or then has knowledge about these subjects... which is the best exam board for each subject?
Also, is it possible to self study these A levels at home?
Currently at sixth form, these are the exam boards that are used for the subjects:
Biology is AQA
Chemistry is OCR A
Physics is Edexcel
Psychology is OCR.

It would be really helpful if anyone can give advice.
Thank you.

I can tell you that Physics OCR B is rubbish and focuses is on obscure areas of physics that don't link in with anything else. I think 'untraditional' was how my physics teacher described at the start of the year
I've just done Chemistry OCR A As level and it was quite challenging but they do say chemistry is the hardest a level whatever the exam board. Although I have to say having just started A2 it looks way harder than As was. I feel like there's lots of just remembering things like what the products are of things reacting and theres A LOT of definitions.
These are the only ones I've experienced so can't really say anything else.

Yeah I have heard a lot about chemistry being the toughest one. We are doing OCR A for chem.