Dao
No longer a newbie, moving up!
I think it all comes down to personal choice. I have a Canon 70-200mm f/4 and also a Sigma 70-200mm f/2.8 (both are non-IS / OS). I like the Canon better in most cases simply because of the weight. I seldom need to shoot in low light environment with long telephoto lens, so lighter weight is better for me.
For other times with shorter focal length lens, if flash is allow, I may shoot with f/4 to f/8. However, my standard DX zoom lens perform better with 1 to 2 stops down from max aperture, so getting a f/2.8 is better for me and the lens is not heavy at all. As for the ultrawide angle DX lens, I usually shoot with f/5.6 to f/11 anyway (may use tripod), so fast lens is not needed for me. So I rather save some money on that. (I used to own a 14mm f/2.8 FX prime lens but seldom shoot at f/2.8)
So I really believe there are no right or wrong answer, it all based on personal shooting style and the type of photos a person going after.
For other times with shorter focal length lens, if flash is allow, I may shoot with f/4 to f/8. However, my standard DX zoom lens perform better with 1 to 2 stops down from max aperture, so getting a f/2.8 is better for me and the lens is not heavy at all. As for the ultrawide angle DX lens, I usually shoot with f/5.6 to f/11 anyway (may use tripod), so fast lens is not needed for me. So I rather save some money on that. (I used to own a 14mm f/2.8 FX prime lens but seldom shoot at f/2.8)
So I really believe there are no right or wrong answer, it all based on personal shooting style and the type of photos a person going after.