Real wood or restructured? I'd choose the black/beech. 

They are both Melamine veneered Chipboard. Not hardwood panels

IMO wood/black. I feel like I'd mark up or spill something on it eventually and a hardwood color top would hide the mistakes a lot better. That and I just prefer the wood aesthetic. A solid color is too plain.

That’s a very good point

Depends on the colour of the room itself and the colour of the other furniture around it.

Rest of the furniture is super neutral. In terms of colour. The walls are a dark blue-grey with natural wood trim, which is making me lean more toward the black/beech

If the trim and the desk's top are the same colour, or close to each other, then that might be a better look when compared to just plain white.

Also, the white desk might "pop out" more when compared to the black one when they're against that coloured wall, so a black desk would be the subtle option, the way I'm visualizing it at least.

Sounds a lot like my room. The wood would keep the theme. Fixing the top would also be easier since it's a simple wood veneer.