But consider this, if you shoot indoors alot, like dinners, musuem, concerts, where flash is not allowed, what would you choose? 1.8? 1.4? or 1.2?
f/1.4. The reason is because even f/1.2 is available, 1) DoF would be too shallow at f/1.2, 2) coma is not well corrected because it is very difficult to do so at f/1.2, so most of the time you'll be stopping down anyway, why pay more?