How important are award redemptions to you?
Delta is actually NOT so bad for domestic awards if you have status.
But for international awards, ESPECIALLY in business cabins (you can not even get first class tickets on any SkyTeam partners that happen to have first class so forget that completely) it is VERY VERY difficult to use your SkyPesos (skymiles).
I've had an easier time redeeming miles on US and CO than on Delta despite having higher status and more miles with Delta.