I'm a 0L, so I can't speak to the actual student experience of either school, but I'll offer my opinion, because I also have offers from Osgoode and Dal and will most likely be choosing Oz.
Like you, I'm not positive what area of law I want to practice, so I'm really attracted to the breadth of clinics and intensives offered by Osgoode. I haven't come across anything similar offered by Dal. I'm not necessarily interested in Bay Street, but it doesn't seem to me that Oz focuses on turning out corporate lawyers.
For me, it comes down to the city. I'm from the east coast and have been living in Halifax for four years and I have never really liked it. There's not a whole lot going on. While I do have a really nice and affordable apartment right next to campus, I'm not committed to living on the east coast and would rather live and work in Toronto, and for me, the extra money/commute is worth the quality of life. I'm not trying to be dramatic, but that's just how much I dislike living in Halifax.
Dalhousie isn't a bad school, by any means. I took their undergrad "Intro to law" course offered by the law school and was impressed with the building and the instruction, but I went to go visit Osgoode and their program just seemed like a better fit for me. The only thing that might sway me would be a big scholarship from Dal, and even then, I don't know if I'd accept.