While customization is fairly decent for Fallout 4, the amount of firearms available is much shorter than previous games, including Fallout 3.
The Chinese Assault Rifle/AK47, or the original assault rifle, or even just the 10mm smg are all missing(and then some more) from the base game. More guns would be a wonderful add-in, especially since finding the same 5 guns over and over is just boring.
I miss the weapons being visible, if for no other reason than the sake of realism-ishness, it also let me know what someone was carrying and if picking a frontal fight with them was going to result in me having my face melted. But it needs to be taken a step further so the weapon isn't just stuck to the character like velcro. Rifles and shotguns need slings, and handguns or similar small arms need some sort of holster that fits them.
The "visible weapons - 3rd person" mod on the Nexus is a good example of what I mean, but I don't feel it should have been something that needed to be modded in.
I hope future updates fix these little issues.