Use the computer.
Aluminum anodization is only a few thousands of an inch thick (0.001" to 0.004" in, about 0.025 mm to 0.1 mm). It's a process that turns the outer layer of aluminum into harder aluminum oxide, and in the process, opens pores in the metal, which you can deposit color dye into (in this case, black). Though the finish is durable, it's still relatively soft, and even something softer like your skin will wear through it with enough time and pressure. Especially in areas like the sharp corners on the palm rests - rub your hand/arm against this every day for enough time, and it will wear down the surface - taking the anodization (and the color) off first, since it's just under the surface and very thin. On non-color anodized aluminum (the silver "color" Macbooks) this wear is almost unnoticeable besides the texture change - the rougher bead-blasted aluminum becomes polished smooth by your skin.
As you use the space black Macbooks with enough time and wear, eventually almost all of the corners will look or start to look like that. The middle area of the palm rest will look especially rough after many years, polished back down to bare aluminum, not to mention all of the small scratches your macbook will get. The added contrast of dark black color against bright white aluminum will make it look much worse than the relatively small contrast of space gray to bare metal.
You see a similar effect on military weapons - they are also anodized black, although much thicker (type II hardcoat). They get heavily used, and eventually the black color wears through. Your Macbook probably sees more handling than a military weapon, and in more areas (a weapon is always held the same way, a Macbook gets handled in many positions) . The difference is the anodization of a weapon is seen as a sacrificial protective coating, whereas the anodization of your Macbook is seen as its permanent color. Much like the paint on a forklift or tractor compared to the paint of a car.
Space black's durability is going to vary based on your use patterns and length of service. If you upgrade often, it's not gonna matter too much. But if you intend to buy and keep it for a long time, even more so if you are a power user using it hands on, just be aware the black finish will wear noticeably. If you care about that, maybe go with the silver instead.