I just ordered mine, also without the tire carrier. You have to be honest with yourself about what you are using your 4Runner for most of the time and what your future mods will be. I drive mine everywhere and can’t see myself constantly unlatching the rear tire carrier just to get to the back. Do I wheel every weekend? No, even when I try to get all my buddies together to go hit up a local trail they bail on me. I can live without the tire carrier. Maybe someone with a tire carrier can chime in.
I've always opted for the tire carrier in the past, usually because I wanted the space where the factory spare sat for an auxiliary fuel tank or better clearance. I use a hitch carrier for my dirt bike these days so I fear that it won't clear with the spare up high like that, but if that ends up being the case I can always switch back to the trailer. If I didn't want the carrier for the space for the eventual LRA auxiliary fuel tank and for my Maxtrax and Rotopax I would likely opt for just the bumper like yourself.