Yes i do agree the light bleed, IPS Glow and blacks (More like GreysAt that time I've used LG 34UC98, which had AW3821DW-like picture quality already in late 2015, while other ultrawides looked like this (that's your PG348Q by the way).
![Big Grin :D :D](/styles/default/xenforo/vbSmilies/Normal/biggrin.gif)
But how much this was due to it being an IPS panel and how much is was due to the monitor build quality i don't know as IPS panels are know for glow & crap black levels but they do have great viewing angles