Are you more concerned about the apparent 'dents' in a smooth surface or the health of the grass in the greens?
I am more interested in the latter. Generally, if I see dents in the greens from the shoes, the course is over-watered or has had extended periods of rainfall.
As I understand it, the old metal spikes cause more compaction, allow opening up of the greens to allow the infestation of rogue species (poa) and also perhaps allow greater infiltration of rain on wet days (rather than surface run-off). These things combine to create that 'donuting' effect whereby the worst part of the green is the middle where the wear has been heaviest from the spikes.
But, I'm not a turf guy, so get a better opnion.
James B