Others are missing normal maps entirely which causes them to be very flat, or have had specularity maps which make the weapons look plastically or out of place. Some of the textures and models are insanely detailed which on my PC actually causes a noticeable delay when equipping them or just trying to view their model in the inventory.
Immersive Weapons has some quality issues that are very apparent. To say that if someone else has a different opinion you should just ignore them is quite rude when the OP is specifically asking for opinions and there are some well documented technical issues with the quality of Immersive Weapons specifically, and this is coming from someone who only uses 1k textures for the most part and keeps things very simple as far as replacement models.