Will the PNP and the diode circuit behave differently?
Given the latest information, see answer below.
 As information is being supplied in occasional small dollops the answer may well change again with time.  

Once all data has been provided the correct answer will be able to be given if anyone is still answering.  

Hint: Tell all you know up front, place known voltage on diagram. If there is a lnown IC driving it show the IC etc.
 If you think the IC is irrelevant to the question then you must know more abnout the answer than is apparent.



Given information as at about April 14th 2013, transistor and diode circuits are similar in effect.
Transistor will provide more current pull down but this should be reasonably irrelevant.   Using a Schottky diode will give lower Vlow_out.

The circuit IS effectively a level shifter. Vout max = 3V3. Vout min is Vinlow + Vbe or Vdiode.