If I hit Start - All then hit N it does not take me to N (read "the first program/folder that starts with N"). The Windows 7 start menu does.
The way to do that now is to click on any letter/heading, which takes you to an alphabet, then click the letter you want to jump to. To my knowledge there is no keyboard way to do that other than paging down.
You can drag, delete, pin tiles. So my tiles are pretty trim. It does take me longer than finding a program that had been pinned to the top of the Windows 7 start menu, but that will resolve with time. I feel that they take more space, but when I'm in the start menu I'm not using the desktop so I really don't care that it's being chewed up.
The dark color scheme is a way to save battery on mobile devices. It also uses less power in plugged in PCs, so we're burning less coal to generate power. I'm fine with that. If anyone thinks it doesn't make a difference, any tiny change made over a billion PCs adds up pretty damn fast.