I still have the same problems in 4.4 as in 4.3. Bluetooth working for a short period and than crashing or wifi unstable.
It's a problem with bluetooth 3.0 keyboards, caused by interference on the 2.4 ghz bandwith. I read there are going to be bleutooth fixes in 4.4.3, but it's not exactly clear what's meant by that.
Sent from my SM-P600 using xda app-developers app