I have been talking about the family of OD/dist/fuzz pedals with manufacturers, players, and some boutique makers. All recommend the same: try before you buy. And with your own bass, not any other.
One of the most complicated effects is the OD/dist/fuzz family, because their behaviour, sound, and adjustments are affected by the bass, or the effect before them. I've seen and heard that some compressors have a very different behaviour depending on the bass. That's why I have fx boards for hi-Z and lo-Z basses. Different beasts.
I thought that output impedance does not matter at all. On paper there shouldn't be a big difference, but ears don't lie. Try a few side by side to compare them against each other.