My older sister got them. I personally think they are not worth it. They have loads of questions on one side and all the answers on the other, which I hated bc it meant it was difficult to check individual answers without seeing the answers to teh next question. The info was also very crowded.
I would definitely recommend just making your own and using them as they will be in the style you remember things and focused on the content you find hard.
I only used the CGP revision guide and CGP workbook, and I liked both of them but physics and maths tutor has loads of exam style questions for free, so even the workbook wasn't completely necessary to be honest. ( I only got both bc my school had an offer where they sold both of them for £10 ish, it's state so they got a deal with CGP where they got the textbooks at made price not selling price or something)
Definitely check if your school does this.
Good luck, I'm in yr 12, if you have other questions abt GCSE/Alevels tag me so I get notifications x