I have the PZ Deluxe as well. I really like it, and have gotten compliments from respected sound engineers on the tone. It's quiet and takes life on the road easily.
I go back and forth with the HPF, it seems a bit high and sucks some of the grunt out of my bass. Recently, I've been rolling back the bass filter to about 9-10 instead and having better results (for now). Other than that I don't actually need much EQ at all. I set it up with good headphones to get the most natural sound I could, and just send that to the PA.
I do miss the idea of the insert points on the PZ Pre, but I don't need the two channels---so I made the choice for the simple unit. (I was planning on a reverb pedal to help my bad arco skills--I decided to practice more.) Otherwise the only issue I have is the crappy AC adapter. I can hear what good components sound like with real power over phantom or batteries, but that thing was short lived on the road for me and it's a convoluted exercise getting pedalboard power to run it. I had an electronics guy make me a dedicated psu that ties under my board.
I've tried a few pre's (fish man, baggs, k&k), and nothing sounded this good (for me). Never tried Headway or Grace...yet.