why are some of the new cards shipping with ver 1.4 or 1.5? I see some older cards with 2.0 even. why is this? is there a benefit/loss of having a card with one instead of the other? can’t you just upgrade?

An older card with 2.0? What card would that be?

I haven’t seen any 2.0 drivers yet, though they will come eventually. But the specification was only officially released this September.