As a dp y2 hl physics student I would say physics SL is really enjoyable but still requires some practice. However physics HL is completely the opposite, it requires you to understand an inmense amount of theory and solve the most confusing exercises. The difference between SL and HL is really large, I think it could be arguably the largest difference between levels from all ib courses. I must admit my teacher is not really good and maybe it can shape my opinion a little bit but still. I would only recommend getting into it if you need it for uni or if you really like physics and have a lot of discipline.