I think it is more than just one thing. I think the price of the Mueller really makes it competitive. Reliability is yet to be seen, but mine held up well in the snow of SD and all through turkey season in WV. I do not baby my stuff and i expect it to last. The different reticle choices was a big plus for me, but b/c of this it is a larger site that sits higher.
The low profile and new changes for the FF III really improve the site. Through my testing and the ease of use for my children really puts this site at/near the top! The customer service and great help I had with them really puts it up another notch as well.
It is hard to say one better, but the reliability of the FF would put it above the QS. If I was to purchase another it would definitely be the FF III.
