I didn't play too long in 3D, I just barely tested the 3D gaming. 720p 2x60Hz or SBS/TB 3D looks awful for me when compared with real 1080p 3D (my PC really does the rendering in 1080p) but the highest possible refresh rate is 30Hz with 1080p resolution which isn't sufficient for gaming.
But I played a lot in 2D mode with games which feature almost-constant HUD elements.
I experienced numerous minor and a few long persistent IR ghost images from game HUDs when my panel was young (<1000 hours) but I never managed to temporarily burn in anything and I can't even imagine how I could possibly cause long persistent IR now with 1000+ hours during reasonable usage (24 hours of continuous gaming may do it but it would also hurt my eye and my brain, so...).
I suppose some people use too low brightness settings for "break-in" and they rush to play games with higher settings after 200 hours or so. But I tell you, this panel requires more than 200 hours of massive break-in (like slide-shows with high peak brightness settings - I mean hight Cell Light, high Contrast and low Brightness setting to produce low MLL and high peak white...) to really get settled in. Otherwise, you should be careful with gaming until you pass ~1000 hours.
"DIY certified hobby-calibrator" (based on ChadB's "warning signs" list