atpX is a lossy codec. If the listener is satisfied with listening to lossy sound, then it is fine. For those that prefer to listen to music that matches the source as much as possible, it is still not an option. atpX-HD is somewhat improved, but it is still lossy.
Another consideration is that atpX has higher hardware requirements than standard A2DP. Both the receiver and transmitter must be able to run the codec, so older equipment likely won't work. Before relying upon atpX, it is advisable to verify that both the phone and the receiver are compatible with the codec.
As for convenience, I find my iPhone and Apple Express very convenient at home, particularly if I am moving around. Moving around the house while using BT will likely cause dropouts or lowered bit-rate transfers. In a car, BT is more viable because the phone is in one place and the noise floor is high. But I hear better quality with a direct connection in the car.
