I am a biomed student and I also have friends doing science.
The bottom line is biomed has a tighter, more close-knit cohort, whereas science has more flexibility when it comes to subject selection. Both prepare you equally as well for med or research.
For biomed, you will need to complete core subject(s) EACH semester for EACH year. These are basically set in stone and you have no choice but to do them. In second and third year, you will also choose selectives and choose a major respectively. For those, biomed students have the same selection as science students (and in addition, biomed students have more choices regarding some niche selectives). For the selectives and majors, you will be doing a subject with science students essentially.
The unhealthy/cut-throat competition side of things that people say for biomed is kind of half true but also half false. Competition is definitely greater than science. But having said that, I reckon the competition pushes you to do better in terms of academics. Few subjects, if any, in biomed are scaled, meaning that most of the time your final score is a RAW score. This means you are not effectively compared to your peers.
The subjects you could take for research, such as
https://handbook.unimelb.edu.au/view/2017/BIOM30003, are open to both biomed and science students, so it isn't exclusive. In addition, if you really like research, you can do honours anyway.