All I'll say is this Ken..
On my two tanks I have running, yes that is my opinion that by eye there is no "noticeable" difference. And since this is fish keeping and not building rockets then if I can't see a "noticeable" difference then to me that is perfectly fine. I am not saying there is not a measurable difference because I'm sure if you wanted to hook up some sort of flow gauge then sure you might see a slight difference, but so what? if it's not "noticeable" then it's not gonna make any real world difference IMO. Not to mention, when did "flow" because the most important thing in a cichlid tank? you still have the same amount of mechanical, same amount of bio, and if you feel you need to move more water than stick a powerhead in there and problem solved. But from my experience with doing this as well as the many others that do it, the difference is not enough to even show up physically so it's not a concern.
Also you can't base flow as a consistent across the board for everyone because we all have difference foam pads, different media, rings, matrix media or what have you in our filters. So person X may have more flow than person Y with the same filter because they have different media that the water has to run through. So who's to say which is best. I think this whole thing is getting WAY blown out of proportion IMO