I do miss it, at times. It's kind of like the loss of Vinyls for the music buffs out there. If anything though, I miss the cartridge the most. It's something I'd love to see a rebirth of much like Vinyls. Because let's face it it was never the box, it was the boxart and the manuels we miss and those are arts lost with the digital age. We see launch icons now, there is no container really. Those used to be the best parts.
Also, storage. I can't have all my games installed at once, I need that data space. I'd have them all uninstalled if it wasn't for the fact that the larger games take an hour to install. Cartridges were plug and play, they were the best... for home consoles I mean.
I agree though, cracking open a new game box, sniffing the plastic, holding the disk/cartridge as you put it in... ahh, nostalgia.