Hrm... I think I'd have to try it but it might make it interesting. And probably cure me of my hoarding tendencies which means there are points in the game where I have to sit there and decide what goes and what stays to pare down on what I'm carrying. Yes, I'm that person that the jokes about hoarding in Skyrim fit really well.
(And this is why I miss being able to use mods in Fallout/Elder Scrolls. Cause I bet you could find some one who would do a mod like this. The one downside imho of being a console peasant, mods for Bethesda games).
Goddamnit, now I just really want to play the new Fallout. And I'm not even done with Witcher 3 yet.
Yeah mods are a huge part of the fun, though I've never seen an inventory overhaul mod that does anything remotely like make it grid based. DayZ's system is quite nice, though not perfect either.
For FO I'd love for them to find a way to use the Vault Boy, and add in Vault Girl, as a paper doll of sorts for your equipment and not simply put a dot next to the items you have equipped. Daggerfall and Morrowind both had a paper doll, though Morrowind was just your character's normal 3D model in a preview window in the inventory, but still it was nice.
Second I would prefer they go back to only 2(or maybe one of each weapon type: rifle/heavy, handgun, thrown) equipped weapons at a time and not full access to everything you have on hand in your inventory. This isn't just to make the game harder or anything but also because I'd like for them to actually show multiple weapons equipped at a time and with some kind of holsters. So you'd have a pistol on your hip, rifle on your back, grenade on your chest or belt somewhere, maybe a javelin on your back instead.
Where they are could also depend on your current clothes/armor. Or your clothes could affect how many you can carry at once. DayZ has chest gun holsters. Maybe we can find various holster to hold more weapons, or mod holsters into our armors. I don't know, that might be a bit too much.
I'd also like there to be backpacks as a means of allowing us to carry more stuff, or really a necessity to do so. But like all of this that will never happen. Lots of people don't like the aesthetic of it and want their character to just look cool.