I'm a proud owner of both, and I love them all.
I feel the M1 Carbine is a more practical rifle for real-world use, because commercial ammunition is far easier to acquire and stockpile, it's very light even with the bayonet attached and its ergonomics (for me) are top-notch. It's superior to carrying a pistol which is what it was designed for, and I feel any target that's out of the effective range of my M1 Carbine wouldn't be worth shooting with the Garand anyway (~100-150m)... I'm in an suburban environment.
I definitely love the Garand. If I have to be in more open, rural areas it'd be nice to have the ability to have more range/power available (and a 16" bayonet, yikes!) - but gosh it's heavy. Plus, aside from the CMP or handloading, usable ammunition just isn't widely available as with the Carbine (ironic, considering how popular .30-06 is)... I guess I should just get the stupid adjustable gas plug and nullify that problem.
I reload .30 Carbine. I am also starting to reload .30-06 for the aforementioned reasion; but .30 Carbine ammunition is just cheaper and easier to get and load. And, I can just waltz into Cabela's or Bass Pro and pick up 8-10 boxes whenever I want, although I pay 40-50 cents a round going that route. I use that ammo for SHTF purposes; my Carbine's my go-to gun.
So to collect; Garand. To use; Carbine.