Lower weapon requirement = higher damage, myth or fact?

Recently I've heard from two people on this forum that having two identical swords, with the exception of level requirements, will have different damages. The lower requirement sword should do more damage then the higher requirement sword because once you have reached the level requirement in your attributes, you have reached 100% dmg of your weapon. For every extra level requirement you have in your attributes, you are supposed to gain around +4% more dmg.

I have personally tested this out myself, with two very similar swords, one was a 15-22 gladius with a requirement of lvl 12, and one was a 15-22 flamberge with a requirement of lvl 8. I had maxed my sword mastery up to level 12 base, and +2 from my helmet and rune which made it +14 sword mastery. I tested it out by killing 3 sand drakes with each sword and I added up the damages and took the average damage of the weapons and did some statistical tests. My results were that the two weapons had no difference in damage.

I'd like to know what others think about this, because not only have I heard about this on the forum but I have also noticed that people seem to pay more for weapons with a lower requirement...

From my own experience, you don't get a bonus for exceeding the requirements of a weapon, just a penalty for not meeting them. THe bonus for lower requirement weapons is that you can get full use of them at a lower attribute level.

It would be WONDERFUL if ANet would make some sort of weapon mechanics listing available so we know such things without endless debate over them.

Guru has a nice chart on bows, and a general damage output calculation(that is just WAY too technical for everyday use) to figure your damage with just about any given weapon, but it would be nice to have a list that says straight up that sword x does a-b damage if you meet requirements and only c-d if you don't.