Donuel
Be careful with yer quantum light. A photon is only said to go through both slits until you measure it, then you know which slit it went through (probably) - they call it "wave collapse" (other terms are available)
A stream of photons - now that is a different kettle of gaps. Each go through one or the other slit and our eyes (& most equipment) averages the result as yer defraction pattern.

I don't know of any experiment that shows a bias on which slit a photon goes through. I guess it hinges on the quality of the slits.

Now Donuel - if you saw two glasses of Schlitz - which one would you pick up, and which was half full and which was half empty?