I just compared the values of Elevit and Blackmores. Taking into account you take x2 blackmores compared to x1 Elevit, and they are both bacically the same. I have heard the tablets in Elevit are smaller and easier to take, but Blackmores is Australian made and owned, where are Elevit is made and owned overseas.
I don't think it would make much of a diference. Blackmores is also a little cheaper, dispite having to take x2 tabs.