I am against the idea of repair turning a item into a +1 item permanently. It would be very detrimental to the already shaken hq market.

I am how ever In favor and always been a fan of the idea that a hq repair could temporarily boost said item to hq parameters.

It could be accomplished by allowing equipment to go to 150% durability. While its durability is over 100% the bonus hq stats would be in effect. Once the item hits 100% durability or lower the buff would vanish. Items that are above 100% durability would not be eligible for repair. Stats added via materia would also not be effected. Finally The only effect a hq repair would have on a native +1 piece of equipment would be the waving of the dark matter cost.

To keep things balanced items over 100% would be damaged at around the same rate as off classed or over ranked gear degrades now. Items would loose there temp hq status upon being trading to another player or placed for sale in a bazzar. I think this could have a very healthy impact on the rate and roll of player repairs verses npc fixes.

I have a hard time trying to think of a negative impact upon the player community. How ever I can not even begin to fathom what kind of a coding nightmare this would be for the development team.