I have naturally straight hair that doesn't tangle that easily, it is mid way down my back. During 2020 I had some major issue with my hair where I was losing a lot of hair. I lost about two thirds of my thickness and I ended up cutting about 20cm off the length.
Which is why I bought another, more gentle Tangle Teezer. Unfortunately when I bought it there was no choice in colour, this shade 'mint violet' and a all pink 'pink dawn'. It is exactly the same size and the 'teeth' are in the same formation as traditional one.
The difference is in the flexibility of the the 'teeth' they are 30% softer than the original, you can feel the difference in it but it isn't a massive difference.
Another claim is 85% less tugging, I don't know how they measured that but I found it pulled hair out of my scalp less than the standard Tangle Teezer. Because the 'teeth' aren't as rigid, it jumps over any larger tangles rather than pulling the hair at the root.
So overall I don't think you need both this as well as the standard Tangle Teezer, I found it helped me to be able to brush my hair and reduce the amount of hair being pulled out from my scalp. My hair is finally staying in my scalp now and growing back, I don't think that is purely down to the hair brush but it did help and I will continue to use this over my standard one.