Is the 1.1 suitable for everyday writing?
Depends on WHAT you will be writing.
For me, a 1.1 italic is NOT an everyday nib, that would be a Lamy XF or F nib depending on what I am writing.
Definitely NOT for taking notes in school or similar situation. The 1.1 would take up too much space on the paper when I am trying to write as much as I can onto the paper.
The 1.1 is for special uses when I want the effect of the italic nib.
However, there are others who use an italic nib for everyday use.