More keystrokes, have to keep track of how many
VIM does it for me. I find two spaces much easier to read.

Tabs are 8 characters
IIRC tabs are actually 5 characters, its been that way since the days of typewriters. Set your word processor to a fixed width font and try it out. Its 5 characters. So the arguement that it is 8 characters and not 4, 2, 12, or pi is bull$$$$.