There is no difference in these 2 options, they do exactly same thing. You can enable the delta Init without data transfer in production system also directly, DTP is a modfiable object in all systems. You do not need a transport for that. After your work, you can keep it back to unchecked.
These options are useful, when you are doing a reload, by deleting the source DSO/cube content, you wanted to update the reloaded data only to one of it's targets, then for other target you will select either one of these 2 options.
lastly, timing also, you may notice fraction of seconds but technically both should be doing the same thing.