No bother at all! I love talking about stuff like this. History A Level is tough, you're in for a long ride regardless of what exam board you do but in my opinion it was definitely worth it because I love History and it gives you very good 'uni' skills e.g. writing long essays and having to speak in a very formal tone etc.
It really helped with my other subjects in terms of writing (I also took English, Geog and Physics but unfortunately it didn't help Physics as you can imagine), even with writing letters and personal statements you have more experience than other students which sounds useless now, but you would be grateful for it in the future.
The only problems would be how much writing is invovled for example, it is a lot of stuff to memorise and is very hit-or-miss in an exam, as because you only get asked a 'few' questions (as essays) if you misinterpret a question you lose a large portion of your A Level which is tragic. You also unfortunately risk growing to hate the topics you study, for example, I love the Tudors, but mainly the things about society (like Tudor medicine, or your average smelly peasant, or the lives of high ranking Tudors) but you have to also learn things about the economy, government etc. So make sure you are very passionate about the subject to override this. Another issue would be that its difficult to practice questions as it takes a long time to do a practice essay, a long time for a teacher to mark it as you can't really mark essays yourself, in comparison to the sciences or maths where you can do a few questions and mark them yourself.
(Wow I really went off on one I'm so sorry) In terms of work load I won't deny it's tough but in my opinion every A Level has its content and learning. History is a lot of memory recall but also understanding, so the easier you find grasping topics and understanding the general timeline/consequences, the less you'll have to sit and try to understand. That's probably why there is so much mixed reaction about workload. It is more content to
memorise than other subjects, o self-discipline and a natural understanding/own knowledge helps reduce the work load.
It's a huge jump in terms of skill from GCSE to A Level, but I definitely did not regret choosing History. It's a lot of time though, so stay on top of everything and read around the subject. I probably said loads of things you've heard before, but I hope it helps! Happy to answer any other questions