Thanks man, I'm glad you enjoyed it :) The whole taking a shot without using the viewfinder isn't for the shot its-self, it's more just a little test of how well you can gauge exposure, although being able to 'shoot from the hip' is quite a handy skill. Mind you, since every new camera seems to have an articulated screen it's a bit of a defunct skill!
Honestly I literally never use any auto functions, I reckon it's probably been a good 5-6 years since I even played with an auto function, most of the time I'll just set my ISO to something that gives me a range in terms of Shutter/Aperture then stick with that, only changing if I go outdoors or indoors. Then it's really quick, literally just the spin of a wheel! I can honestly say the speed of changing settings has never been an issue. I think it just forces you to think not only about exposing the shot, but which element of the shot you're exposing for!