I have a friend in my chemistry class who got a B in chemistry GCSE. She found it difficult, but she worked hard and had been getting Bs and Cs in her mock exams. I won't know what she got in AS until August 13th. I think it depends on what you're aiming for, since she needs a B overall to do biomedical science.
Everyone in my class found chemistry hard in at least one topic. Usually it's Hess Cycles, but others found memorising mechanisms harder. For me, the hardest part was learning the reactions and their conditions because I just didn't enjoy it. For my exam board, we need to know something like 50 throughout the whole A-level syllabus.
If you worked hard, it wouldn't guarantee you a pass. It isn't just about hard work, you have to really understand what's going on and how to write that in an exam-style answer. I think, for most, that is the hardest part. For this, you will need to find past paper mark schemes since I doubt that the required answers have changed much with the new specifications. Write notes based on the mark schemes, answering every specification point.
Despite the above, I quite liked chemistry. It was satisfying to know about something that looks complicated, even though it is less complex than it looks. Also, lab work could be fun sometimes, what with all the different coloured chemicals, and making nice-smelling esters. I'm hoping for an A or a B for AS, and an A overall.
Do a level chemistry if you are interested in chemistry, or if you need it to meet entry requirements for a university course. Though if you need it for uni, but don't want to do it, you might want to reconsider which course to do. I'd recommend that you look through the chem specification that is specific to the exam board you'll be studying from. That way, you can see if the topics interest you.