Wow - got it working finally.
Tried downloading the "official drivers" from Broadcom and they don't do nothing, don't even compile. Eventually figured out I needed to use b43-fwcutter to install the firmware for this card (why can't Broadcom mention this on their website???)
Followed the instructions here
and downloaded b43-fwcutter from here
Compiled it, installed it, and then run
b43-fwcutter -w /lib/firmware/ wl_apsta_mimo.o
and the good news is it's now working!! Yes!
Don't know why it works under puppy linux straight off - maybe they included the firmware or something in the distribution??
Just thought I'd mention it here so in case anyone else is looking to get one of these cards enabled.
One things for certain though - unless it comes built into the laptop I certainly wouldn't buy another Broadcom adaptor again considering how much they make you do just to get it to work!