Here's another user's impression of RedRock vs O-Focus:
And the definitive thread on the O-Focus DM
The truth is, no matter which FF, you'll find people who like it, and some who don't.
And when we buy something, we tend to have a confirmation bias, to protect our own egos.
There are a lot of threads on FF, many on the Epic forum and on the Accessories forums.
You have to spend a whole lot of time reading to be able to read between the lines and perceive quality differences.
Best if you can hold some of them in your hands and see how they actually work and feel.