It's cool to see other physics duders on the site! I recently graduated from a four year physics MSci and overall I enjoyed it. You have to really like the subject otherwise you'll get bored or frustrated very quickly. My modules in the first two years weren't that bad (apart from having a lot of lectures) but in third and fourth year things got significantly harder. Fourth year was quite brutal because we also had a major project (essentially doing your own research with the help of a supervisor) that if you didn't keep on top of from the start could leave with a lot of work and not enough time. Apart from final year I only occasionally had to do reports and even then they were quite simple. You might have to do spreadsheet analysis in your labwork because that's the best way to analyse data in a lot of cases. Again, that's not especially difficult.
I don't regret not picking another subject. The way degrees are taught in the UK is different to the US. Over here you just do the subject of your degree and can't take modules in other subjects. If I had the choice I may have taken a few modules in engineering, maths or another physics related subject but we don't have that option.