There is some differences quality stilts, and some of them are very dangerous, i think you should know that and not always just say about quality.
I am sure this will help you guys to differentiate between them.
So this are 3 main differences and USUALLY - not always- you will see all of them in one stilt, and sometimes you will see just some of them.
First, it is the most important thing: behind the twins muscles:
In the left part you will see the bad quality and in the right the good one, that is for all the pictures.
You can see that it's caught with 4 rivets, which is super dangerous, it is not holds on for a long time and it's just broken after couple of monthes. I almost broke my leg for that twice.

Second thing is the footlever, if you have this bending there- so you probably have the poor quality stilts.
This footlevers are become broken after some time it's depend how hard you bock and how much, but it will break after a while.
I broke them 3 times and I know some more people that it happened to them too.

Here you can see the crack that I am talking about, with some more bocking it will break for 2 parts.

The last thing that you will see here is the axle or what ever you want to call it in English,
We have 4 of them in every stilt. in some stilts you will see a mix from the good and the bad quality.
Like always- the bad quality is in the left side and it is not hard to see that.
you can see that it is a plastic and not metal like it should be and it is being worm down very fast and the stilts starting to be noisy for that.

So this are the main differences and if you know more let me know.