1) The energy efficiency of Bluetooth devices will greatly differ as 
will the hardware and chips they have built-in. Or said differently: a 
VW Lupo may run up to1000 km with 30 liters of fuel. A BMW X3 might 
only be able to get as far as 200 to 250 km with the same amount of 
fuel. Now the BMW X3 doesn't need so much fuel because of a software 
problem. You can't compare BT devices as if they were identical just 
as you can't compare cars as if they were identical.

2) Apple ships its own drivers and can optimize both drivers and 
hardware to play well together. These drivers run as kernel extensions 
and thus must have direct access to the Bluetooth stack - something 
that's not available to anybody else. The regular BT API for 
developers is entirely user space based and certainly lacks a feature 
or two that is available in kernel space.

3) The BD Remote support is based entirely on findings that have been 
made. Sony does not document its remote control. Thus, it's not only 
unknown whether special power saving features exist nor how to access 
them should they exist.

Best regards, 
Felix