There's two ways that A-level English lit works and that's either set texts or no set texts. For example, AQA A English Lit does not have any set texts for their exam (apart from poetry anthology) but the rest of drama and prose-testing is based on the student's wider reading which makes the exams difficult because you have to know a lot of texts inside out including your own wider reading in poetry! The other is set texts - I can't mention this as I have no idea how they go, but I'm guessing it's easier....
You have to be really committed to English Literature... I don't know what to say as it's one of those subjects you either see the point or just don't see the point so at A-level you have to open your mind even more and try to get many different intepretations as you can from one quote which is very thought-provoking.
Workload gets intense especially depending on the size of books you will have to read. For AS, we had to read Birdsong which is 500-600 pages long for one essay and then compare two drama texts also which was tough for coursework. Alongside that, we were reading another novel for wider reading and started to get to grips with analysing 40 poems in class which was the most mind-numbing thing ever!
A2 gets really intense as you actually will most likely deal with literary criticism which is quite good and that got me motivated for uni this year because it's something you never heard of when you're at GCSE. The content is a lot harder because your comparison for coursework will be usually based on 3 pieces of literature and different genres which is really hard to compare and control the level of accuracy you have to go. Oh and above all, be prepared to reread your coursework texts not once, not twice, but about 3 or more times to get quotes and to get quotes to compare with other quotes, understand plots, structure and more quotes... This does get a bit tedious but the great thing is that every time you reread it, there is always something new you pick up which makes it easier to get through.
I studied GCSE English and never did the pure English Lit GCSE... So it was intense especially doing Language too. But I think the hardest part for me was HAVING to read something I didn't enjoy and that sucked almost all the joy out of Lit. I am strong with analysing language and form but structure is so difficult for me. Oh, also the amount of literary terminology we had to revise was just stupid! However, I would give it a 8/10 because of my experience. You may find it easier/harder depending on the books you read.