Ok, for tuning purposes the hand controller does basically the same as the datalogit. BUT there are a hell of a lot more fetures which imho make it worth the little extra...do a search and you may be suprised what you can do with it from SK:
OK, but only the ones that you can't access via the Commander
Inlet air temp fuel map
Water temp fuel map
RPM acceleration fuel map
Cranking Injector dwell map
Water temp versus boost fuel correction
Inlet air temp versus boost fuel correction
RPM Load Point table
AFM load point table
AFM voltage table
Ignition versus water temp correction
Ignition versus inlet air temp correction
Ignition dwell versus RPM correction
Ignition versus battery voltage correction
Ignition versus boost correction
Individual injector trim
Injector lag versus battery voltage correction
Via the Datalogit there is also;
Antilag via injection
Antilag via ignition
Intercooler spray
Basically anything that you want to turn on or off
Then there is the logging
Every standard sensor is logged
Plus 4 others (eg; lambda, brake temperature, suspension travel etc etc)
as well as :
All of which are important once you reach the limitations of the stock afm/load point base map setup.
Swapping to a Z32 or VH41/Q45 AFM does zilch in its own.
Software is required.
There's also the A/C and non a/c overheat fan temp switch.