Smaller tiles would be great! Unless there's some live info to display, the tile only needs to be big enough to show what app it's for.
I don't expect my opinion on this to be popular here, but to me the Modern UI as a whole wastes a lot of space. I first thought about it on WP. People complain about the "boring" rows of icons on iOS & Android, but they are a much better utilization of space, which is especially valuable on a +/- 4" screen. For example, when I go to the app drawer on my WP I can see about 8 apps without scrolling. On my Android I can see 25 apps.
spaulagain, I know you're a Windows fan all the way, but as a designer what's your honest opinion? What are the advantages to making everything bigger that outweigh the disadvantage of higher real estate use?