Hey! I'm currently in my third year at the University of Nottingham so I thought I'd drop a message.
I ended up picking Nottingham over Imperial as I'd heard the student satisfaction, and research was better. As they are all IOP accredited Russel group unis, the standard course will be pretty much the same wherever you end up.
Regarding course flexibility, the first year course for all 'physics' and 'physics with' courses is the same. It gives you a chance to try experimental, theoretical physics and is useful if you're struggling to decide between the two. There is also a module called Frontiers in Physics that everyone does in first year. It cover the three main research groups: medical physics, astrophysics and nanoscience. A lot of people end up switch between the 'physics' and 'physics with' courses after first year once they start to figure out what kind of courses they like.
In the second year, if you are on the standard physics course you'll do labs but if you are on theory, at this point you get to swap of labs for 2 theory modules. There are also 2 optional modules you can take and there's loads of choice on what you want. Some people pick stuff from other departments too if they're interested in it!
Third year there's so many more optional modules and a lot of people say its their most enjoyable.
As for the masters, if you choose to stay on, there's no/reduced exams based on what modules you pick. The year is spent doing a year long research project and modules studied in intensive blocks. It focusses on developing soft skills, following discussions with employers.
Ultimately, I'm sure you'll be happy wherever you end up! This has just been my experience so far but please feel free to ask if you have any questions
