I'm undecided between the EHX Pitchfork and the Digitech Whammy - they both have the features I want and both track really well as far as I can tell. But does the Whammy suck your tone?

The 5th generation whammy has true bypass. I have the Whammy DT (which is the Whammy 5 with the DropTune) and I've no issues with it sucking my tone while it's bypassed.
Just got one a week ago, there's no difference at all whether you have it in your signal chain or not. Epic pedal. I should maybe post a NPD here, I took photos and everything but forgot about posting them. I also received a nice fuzz pedal that day
It doesn't suck tone.
There's nothing that could make my "tone" suck any more than it does already.