Latest Oled or IPS are pretty equal, slight difference at max. Nothing to worry about displays.
Colors are boosted (saturated) in oled while they are natural (more accurate) in IPS panels.
Contrast ratio difference is almost irrelevant now, because most high quality IPS displays have excellent contrast ratios, and they show "almost" as deep inky blacks as OLED.
In my basic daily usage (basic internet surfing, video streaming, music etc), GF2 got hot but did not overheat (stayed smooth), but it did stutter and hiccups (due to throttling, high temperature) when pushed hard (especially outside in day time). So it was inconsistent performer and gets hot pretty quick. Rest it was good, not bad. It was 100% original (purchased brand new from abroad).
If you got hands on a refurbished, faulty or repaired, then heating could be too much of an issue. That's the problem.