There really aren't all that many items you can buy and be totally happy with right off the shelf without some suggestion as to how it could be either better, or just more functional. I have several types of quivers and use each in different situations.
Here is a modification I did to the GFA quiver. It took some playing with, but I finally have a configuration that does what I need it to do. I can fit 7 arrows and it now stays in place on my side or back.
Problem 1) a nylon strap NEVER stays in place so, I replaced it with leather. This one is just a cut from a raw leather belt from Tandy Leather, I just dyed it. The length is not adjustable without an allen wrench now, but is perfect for my applications so I don't care. I "broke" the belt in by working it/tightly rolling it in different directions so it was quite pliable.
Problem 2) It took a lot of playing with the parts that came with the quiver until I found a configuration that allows me to fill the quiver up. All but the way I settled on pressed on arrows, or didn't allow one to be in the quiver. Picky, I know, but I am pleased with the result.
It rides nicely with the back of the quiver against me flat, and still full to capacity whether on my back or side with the hood facing forward and the fletches back. When I shoot I just shift it so that the fletches are up and hood down on my back.
Here are a few pics. I will take function over beauty every time.