I ended up buying the older F1, why?

The F1+ was $2199 + $240 in shipping, so $2439.  The older F1 was $1,350 with free shipping.  The older F1 I could run with a spare HP server power supply I have, the F1+ I’d have to buy a $200 or so 1300w PSU, so close to $2,700, so 2x the price for not 2x the hash power.  Leaves me enough in pocket for other gear or a future update to the F1+, if and when it comes out.  Power usage was similar when evaluating efficiency, but when calculating efficiency along with price efficiency, the F1 won out for me.