There is no difference between using a Short or Byte buffer, it is just two representations of the same underlying data.
The only difference I can think of is that you are limiting your options on how to access the data during recording, since in short your minimum data representation would be 16 bit (short size) but then again you can just xAnd any part of the short object to get one of its bytes.
if you are doing a real time audio processing of any kind you better use byte to easy data minipulation.