I'm not sure what you mean by "plenty of reads on how rowa is the best", but anyone can post whatever they want on a forum such as this. Just like you said rowaphos is the best, but what do you have to back that up with? As far as I know, there have not been any lab controlled, scientific studies done on the different types of GFO. Granular ferric oxide works by binding phosphate to itself. Does a grain of rowaphos bind more phosphate to itself than a grain of another type of GFO which may be half the cost? For rowaphos to be cost effective, it would have to bind 2x as much phosphate as the Bulk Reef Supply GFO, for example.
Does rowaphos work? Yes it does. Does the cheaper BRS GFO work? Yes it does. Which is better? No one can say for certain until controlled studies are done, and those studies are not cheap. Would a certain manufacturer want to fund that study and then publish the results if the study shows their particular GFO isn't the best? Probably not, which may be why it hasn't been done yet.