Hi there,
i'm currently in my final year of studying Biomedical Science at Hull so thought I would give you a quick reply.
With regards to the 4 year Masters course, you have to understand what you're letting yourself in for. You have to achieve consistently high marks to keep in line with the requirements of the course and if you don't, then the department definitely isn't afraid of moving you to the 3 year course! I know a few people who have switched from 4 year to 3 year purely because of the immense stress it has caused them. By all means go for it, just understand it's very hard work!
If you have any other question please feel free to contact me