I'm not going to go on about which I think is best or why but I will say that till the end of this month you can buy BFD Eco + Platinum samples rock legends for a mere $49.
Platinum samples rock legends normally retails at $59 whilst Eco would normally set you back around $79.
So I'd say financially there's only one choice right now.
I'm a huge fan of Fxpansion because I love the sound of raw unprocessed drums that are extremely well recorded.
It has far more scope for tweaking and creating your own sounds in my opinion.
And the sounds are much less processed which may not be what you want of course.
Oh sorry, I wasn't going to go on about it
Here's a link to their special offer
BFD Eco sale Steve
Also as has been pointed out if you have anything that pre-dates windows 7 you can only run it in 32bit.
I think this is a bit of a misnomer to be honest as the only (or main) reason people were needing 64bit was to take advantage of the extra ram that could be used.
BFD Eco was created for slower machines with less ram so the 64 bit thing is no big deal. It runs perfectly for me on windows 7 32 bit and has no issues with bitbridge.