It was my understanding that aptX is a higher quality way of transmitting music over bluetooth. AAC is a type of music compression, and not really related to wireless or BT, no more than MP3 is (which AAC is competing against).
Isn't comparing AAC to aptX something of an Apples and Oranges comparison?
FWIW. I agree with UBS28...it would be great if Apple could throw in aptX support for those of us that that don't want to buy a W1 chip-enabled device FROM Apple. It's a great standard, can be lossless, HD, etc. Why not?
I should add, too, that aptX has been out much longer than Apple has had the W1 chip, yet no iPhone has ever supported it.