Yesterday I had some time on my hands, and I had been meaning to do this test, so I did it..
I have the SuperShieldz Tempered Glass Screen protector on my Note 4. I like the fit and the looks, but I wanted to see how it looked up against a NAKED Note 4.. I went to a BestBuy store.
I know I got old eyes, but my Note 4 looked brighter and just as sharp as the Naked Note 4. I went into the setting to see where the brightness level was on the naked Note 4, and it was set all the way, just like mine. That assured me that nothing I can see where the temp glass screen is taking anything away from the resolution. Will do it a couple more times, and get some other eyes involved too.