The console on the Forester is higher than the WRX/Impreza so the OEM shifters are about 2.5" longer on the OEM Forester levers than the Impreza. The KB shifter specifically for the Forester still has a short throw but the shift knob is only about 1/2 lower than stock. I'm guessing the KB shifter for the Impreza on a Forester sits pretty low. I just mention it because some people may not like it down that far but then again they may prefer it
Here is my install for the F-XT
And a pic:
As you can see it's not exactly all that high with the longer lever. Do you have a pic where the Impreza one sits? I'm curious.