I don't have 4.4 on my Nexus 7 just yet, which is what I'm currently using for testing. I can't stand using the emulator as it's incredulously slow and unable to fully test Bluetooth capabilities. Although I have both the SDK's to compile it for 4.3 & 4.4. I can't imagine Bluetooth APIs changing much between the two, which is fine for the moment. I'll get to 4.4 eventually, hopefully. Lol.
Yeah I've found StackOverflow to be very helpful; I may just have to start querying there directly.
Why not 4.4? I found stackoverflow to be invaluable for Android development.