I bought a squeeze bottle of Haddar mayonnaisse. It visually looked fine in the bottle, but the moment it hit the matzah, it turned back into oil. A matzah sandwich isn't all that great to start with, but this was just disgusting. (a choice between a completely dry sandwich and one with oil dripping through the holes of the matzah. fortunately, i had ripe avocados ready to replace the stuff)
This was actually worse than the Manischevitz breakfast/energy bars I bought a number of years ago that tasted like bubble gum.
Not sure what brands I've bought before, but I'll avoid Haddar in the future.