I graduated from Western’s Med Sci this year and will be attending Western’s medical school in the fall. I can’t speak for Waterloo but I loved my program! If you pick the right courses and modules, it isn’t too bad to maintain a high GPA. I agree that being an extra hour away won’t make a big deal in regards to visiting home. I visited home (GTA) about every 3 weeks with the Greyhound or rideshare.
If you’re concerned about missing out on co-cop, Western has an internship program that works similarly. Basically, at the end of your third year you can apply to do a full-time internship in your fourth year. Friends of mine have worked for the Ministry of Environment, Robart’s Research Institute, Sanofi Pharmaceuticals, and Labatt Breweries (all in science/lab related jobs). Because there’s usually few people who apply to the internship, it’s not that competitive to get in. Not sure how long Waterloo’s co-op program is but the Western internship route will take you an extra year because you’ll need to finish your degree requirements in your 5th year. So you’re still getting the relevant work experience, similar to Waterloo’s co-op and you don’t need to decide on whether you want to pursue the internship until 3rd year.