I said it's your opinion that haste is the most important gear choice that people can make in this game.
It's can be an opinion based on what context you use it in. It also can be a fact based on what context you use it in.

For example: In terms of trying to evade a monster, you may have an opinion on what is a good balance of haste and evasion that may differ from someone else's.

It can also be a fact

For example: If damage is your number one priority, then x amount of haste is going to beat Y amount of another stat. This either happens or it doesn't happen depending on the value of x and the value of Y. Either way you look at it though, would be a fact in the scenario, not an opinion.