Hi Guys, thanks for your replies. I've narrowed down to BD and M&M as suggested, and was also considering Aeroplan.

Which would be the best of these 3 for me? How do redemption rates/opportunities compare? Most of my redemption would be to places like the US, where I'd like to fly in J or (if there's a big diff as in BA) in F.

Does BD participate in *A upgrades? Does LH status match if I have BA gold and AA Plat?

As far as Aeoplan is concerned, I wasn't considering it very strongly as not mentioned here and since I don't fly AC, just thought what you'd think about it.