I do not think an SPG is worth 2.3c
When I use an SPG card instead of my 2% cash back I get 1 point = 2c cost
Also it overvalues Continental miles and undervalues AA miles significantly.
CO miles can't be used one way.
AA gives great OW awards, has lifetime status for 1MM miles does not block and has great award availability.
I could go on and on...