Fallout 3 used RPG mechanics that caused weapon spread based on character stats, so unless you put points into gun skills you're going to have a hard time by design.

I've beaten all three modern games on console both VATS and free aim. Fallout 4 has by far the best shooter mechanics, it's what ID software does. Iron sites in Vegas certianly helped as an FPS, but it also removed the RPG gun spread and replaced it with requirements to use the various weapons. This made your ability with guns binary, you could either use it or you couldn't. In 3 it was a progression.

In the end, I guess it just comes down to taste and what you are looking for in the game. Its Bethesda so you know there is going to be jank. The shitty collision objects in 3 were always far more a problem for me than the weapon mechanics.

Having said all that, I've been watching the development of this mod for a long time and wish I had a PC to play it on.