When I hunt public land where I know guys will be coming in behind me, I will get there pre light. Usually 45 minutes before light, as long as I know my approach will be quiet.
On most Private lands,I will walk in just as its starting to get light out. "gray light" as some call it, unless I think I will be in an area where I expect deer to be at, first thing.
Honestly though, I have found little difference in deer sightings either way except when I make a racket in the dark trying to find my tree.
I do think there is some benefit if you are hunting farm country to going in at first light because you can see deer in the fields and figure out an approach.
Everyone has an opinion, but I say go when you can. Personally, I love watching the woods come alive and wake up.