Anyone that has used a 5-hit has any right to say anything about it.
First hand experience is great for the person but really, bad for the comparison unless you've used both. You can't make decisions based off just doing things one way and that's it.
Making decisions for "But I enjoy it!" is fine, too. They are VALID for your choice in doing something yourself. But, they hold no weight whatsoever when you're trying to help other people make a decision. What does hold weight? Your theoretical paperwork.
If you haven't, keep your theoretical paperwork to yourself and find somewhere else to backseat drive.
This is a forum. It's a place to communicate about things. Specifically, it's a forum to talk about FFXI and improving our overall knowledge and experience. This particular thread belongs in a forum for SAM and discusses exactly this issue.
Want to know what's interesting about all of that? A lot of the information that people swear by and build their knowledge off of started as "theoretical" paperwork.
Theory has a place. It's used to determine generalities. It's used to compare apples to apples and oranges to oranges. It's used to build a theory that can direct people in making choices. It's solid, it can be repeated, and the outcomes have been shown to come really close to application.
You've had the math shown to you for why a 5-hit just isn't as good as a 6-hit. You can rage all you want, but the sad truth is... Math doesn't lie. You can accept that you're using your 5-hit specifically because you enjoy it (and that others will mock you for your choice), or you can experience the joys of a properly built 6-hit. Your choice.