The subject line pretty much says it.
I bought a baby scale that was also promoted for small animals, and had a lot of positive reviews on Amazon. It was worthless. It consistently read at least 30% low. (I compared it to two kitchen scales, and for heavier weights, a bathroom scale.) It didn't even give stable readings -- once I placed an object on it, the reading kept ticking down until the scale's timer turned it off.
I asked my vet if they could make a recommendation. When they got back to me, they recommended the same scale.
So I'm at a dead end. Maybe I just got an individual bad scale, but it's so bad that even if I exchanged it for one that worked perfectly, I would never have confidence in it.
Can anyone make a recommendation based on experience?

Hello! I came across your question and wanted to offer a suggestion. I have never used a pet-specific scale, so I don't have any recommendations there, but I wanted to share what I do to monitor my cats' weight.
I just use a regular human scale but place a small box on top to put my cat in for weighing purposes. Because they're designed to step on and off of, human scales generally don't have a tare/zero function... so if the box you're using is heavy enough to register, I'd just make note of the weight and subtract that from the total after you weigh it with your cat in it.
Another option I've seen people recommend on Reddit is to use a luggage scale. These scales have a hook you use to loop around the luggage handle then lift it off the ground to get the weight. I'd imagine you could easily use it to weigh your cat after putting them in a carrier or something with a handle you can hang off the luggage scale. The one I use has a function that you can zero out the weight, so you could weigh the carrier itself then zero out the scale and weigh it again after adding your cat.
Hope that's at least somewhat helpful!
- Kate