Basically, there are 2 different major versions of the LEGO IR Receiver, the unmarked V1 and the labeled V2. I've also read somewhere there was also a small hardware upgrade to the V1 Receiver at some point, also unmarked, dubbed V1.1.
The V2 IR Receiver came in the 2012 set 9398-1: 4x4 Crawler, and is apparently a much better piece of hardware than the V1 series. However it has yet to appear in any other set, or by itself, at least under that label. Some people have speculated the hardware was again silently upgraded, and the hardware on new ones is the newer hardware, without the V2 label. On the other hand, I know someone contacted LEGO customer service about it, but got an unconvincing response that the one they sell by itself is not the same as the V2 (unconvincing, because they didn't seem to know anything about it at first, and were possibly using the same internet resources we have available).
So my question is:
Is the V2 hardware widely available in new products? If not, why is it so rare?