Depends. Grids usually mean less stuff to store, but it balanced gameplay in Resident Evil 4 by giving enough room to carry weapons, ammo, and supplies. RE5 was just crap. It would take a lobotomized chimp to see the sense in saying a weed takes up as much room as a grenade launcher or a piece of equipment I'm wearing. So, there's less room. However, unlike encumbrance, I can quickly pick out what I need and get back to what I'm doing because it's right there in plain sight.
Honestly, I wish inventory was handled more like my files in Windows. Let me file them, let me switch if I want to see pictures or words. I'll make it a lot more efficient for me.