It's installed when I want to play it. Usually the counter I hear is that internet is fast enough where that isn't a problem. This is an argument, that gamers use to contend when the idea of online only was considered by Microsoft. The fact that I can preinstall 100GB of data beforehand at my leisure is worth it.

Especially now considering that steam offers free refunds up to 2 hours of gametime or 15 days after release? Realistically on PC there is very little reason to argue against it at this point in my opinion (obviously this is referring to PC, no need to do that for Consoles that don't provide these opportunities.

This isn't really a pro preorder, I just lost my frustrations with it when the risk was mitigated