Re: 5 speed vs 6 speed, which is faster/more responsive?
The everyday automatic operation of the WK2 5 and 6 speed is identical, the only difference is when you attempt to manually control the shifts.
The WK2 Hemi gear selection and shift pattern has been a subject of discussion for over a decade. Factory information is not all that clear. Those that try to reverse engineer are confused by the control software and lock up torque converter which make it appear that there are 8 distinct forward gear ratios.
Bottom line to address the OP question and as stated before, the WK2 5 and 6 speed transmissions are identical. The computer is programmed with a couple manual mode differences:
1) When driving at highway speeds and you tap left, the six speed will disable MDS and display a 6. The five speed will display 5, shift out of OD2 (6th) to OD5 (5th) and disable MDS.
2) The 6 speed allows the driver to select both second gear ratios where the 5 speed does not.
Otherwise the function is identical and in everyday operation the performance is identical.
The 2014 8 speed is a different animal with entirely different gear ratios.
2011 WK2 Overland Mineral Gray/Black, Advanced warning, V8; 2009 KK Rocky Mtn V6; 2000 WJ Laredo I6; 1979 CJ7 I6... green... miles of smiles :)