Out of 70 amps, I've only hated a handful. The rest of my journey has luckily been positive, and I've honestly liked to loved every other amp to pass through here. Of course voicing, gain structure, tone, how an amp feels under the fingers...these are all subjective things, but for my taste, these amps didn't last more than a week, and I can say that I actually hated these four:
Armored Amps Sabot-(Worst amp I ever owned). The overall tone, voicing, and gain structure was horrible and the loop was extremely noisy.
Diezel Dmoll--(2nd worst amp I've owned) Flubby, bloated, overly low mid dominant mess with no attack and grind.
Peavey Invective (3rd worst amp)-Lifeless and sterile as could be. Horrible tone, voicing, and gain structure. Just sounded awful.
Friedman BE Deluxe 100w (4th worst amp)-Gutless, no punch/balls, voicing and tone just did not sound right at all. Just sounded off.