Hi there, I am currently a student attending Bellerbys College in Brighton, doing my A-Level and hopefully will graduate this year. I can't talk for Bellerbys Cambridge, but I can give you some ideas about studying in Bellerbys Brighton, especially when you want to pursue your medical degree.
I'm proud to say that Bellerbys Brighton has great teachers in the Science department (I've been there since GCSE so I do know almost all of the Science teachers and how they teach), and the Medic Tutor Group (homeroom designed special for future medical students only - this includes veterinary science) is efficient in giving you the preparation to apply to a medic school. For example, they give you a trip to the hospital in Sussex, gives you anatomy class during tutor sessions, et cetera. I can't cross my fingers on this since the head of the medic group changed this year, so it can change once you arrive.
You do need to go for an interview in order to join the medic tutor group by talking to the A-Level Programme Manager at the start of the year and sometimes they assess your Maths and English. I'm not sure about this because one of my friends can't join until she has her English Proficiency prove, but some of them don't even have to do it.
My advice is that if you really come to Bellerbys Brighton to join the medic group, you should show consistency in your grades and always be motivated because honestly, the medic group is the strictest and the most intense tutor group. The pressure is real! Many of my friends dropped from the group due to the pressure and competition. They do warn you about your grades, and if you are in the medic group you can't join the school's student union. A guy was chosen to become the president for the student union but our Headmaster and A-Level Programme Manager advised him to leave the position to someone else because of the work he has to do to get into a medic school.
Be prepared. Teachers are amazing and surprisingly friendly. I assume you're going to take Maths, Biology and Chemistry because they are the required subjects. Our Maths, Biology and Chemistry teachers are great. I've been with all of the biology teachers here and there's only one of them that I personally claim to be a 'bad teacher'. But the chances for you to get her as a teacher is probably... not sure. Just hope for the best. For sure, they always assign the best math teachers for the medic students, verified.
But in the end, everything depends on you though.
The drawback of studying in Bellerbys for me is that teachers show favouritism when they claim that they treat everyone equally. This is a common problem involved in Brighton's science department. Sometimes this motivates me to study harder so I can be like those people they really like, but most of the time it emotionally wrecks you. And schedules are not designed greatly, sometimes you have 4 hours break which will make you feel sleepy during afternoon / pre-evening classes. Securities and staffs are annoying, but in terms of quality in learning, the science department is the best opportunity you can get.
Wish you the best, and I hope you can achieve your dreams! Just hit me up if you want to ask further questions about Bellerbys Brighton.