from my experience, low quality panels (all of which i've tried are non-IPS) need to be at a certain brightness to hide their non-uniformity. unfortunately, i like my screens a little darker than normal because i stare at them for long periods of time. after calibration, my previous non-IPS panels had different color temperatures at different areas of the screens. at high brightness, which is what they show at a store, the problem would go away (or be masked imo). my old IPS panel still calibrates to match nicely with my newer IPS panel.
that's not to say all TN panels are shit. you just need to do your research. read the reviews on
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