Standard Award. 15 credits just sit there until they expire.
Termination of A+ Rewards is a one-time opportunity to convert credits to points. I don't plan to use that, but some people will.
My current plan is to create as many Standard Awards from Credits as I can, maybe topping off one by converting points to credits then leave a "seed" for a future top off in both my wife's account and my account.
Since I don't generally keep large amounts of credits in my account it should work out for me.